View Filing Data

Number of states in which entity operates

Number of states in which entity operates

[1]

The carrying amount of the Series A Preferred Units, reflected as Preferred units - unconsolidated affiliate on CenterPoint Energy’s Condensed Consolidated Balance Sheets, was $363 million as of both June 30, 2018 and December 31, 2017. No impairment charges or adjustment due to observable price changes were made during the current or prior reporting periods. See Note 2 for further discussion.

New Accounting Pronouncements (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Accounting Standards Update 2016-15 [Member]
Effect of change on cash flow activities due to adoption of new ASU			$ 1	$ 3
Accounting Standards Update 2016-18 [Member]
Effect of change on cash flow activities due to adoption of new ASU			(2)	8
Accounting Standards Update 2017-07 [Member] \| Operating Income [Member]
Increase to operating income and corresponding (decrease) to other income from the adoption of ASU 2017-07	$ 15	$ 17	29	34
Accounting Standards Update 2017-07 [Member] \| Other Income [Member]
Increase to operating income and corresponding (decrease) to other income from the adoption of ASU 2017-07	(15)	(17)	(29)	(34)
Accounting Standards Update 2017-07 [Member] \| Houston Electric [Member] \| Operating Income [Member]
Increase to operating income and corresponding (decrease) to other income from the adoption of ASU 2017-07	8	7	15	15
Accounting Standards Update 2017-07 [Member] \| Houston Electric [Member] \| Other Income [Member]
Increase to operating income and corresponding (decrease) to other income from the adoption of ASU 2017-07	(8)	(7)	(15)	(15)
Accounting Standards Update 2017-07 [Member] \| CERC Corp [Member] \| Operating Income [Member]
Increase to operating income and corresponding (decrease) to other income from the adoption of ASU 2017-07	4	6	8	11
Accounting Standards Update 2017-07 [Member] \| CERC Corp [Member] \| Other Income [Member]
Increase to operating income and corresponding (decrease) to other income from the adoption of ASU 2017-07	$ (4)	$ (6)	$ (8)	$ (11)

Proposed Merger with Vectren (CenterPoint Energy) (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Amount of cash to be paid to acquire Vectren	$ 6,000
Cash to be paid per share of Vectren common stock prior to closing of the Merger	$ 72.00
Short-term debt	$ 0	$ 39
Anticipated amount of short and long-term debt at the closing of the Merger	2,500
Vectren [Member]
Short-term debt	248
Long-term debt, including current maturities	2,000
Termination fee	150
CenterPoint Energy [Member]
Termination fee	$ 210

Revenue Recognition (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

Jun. 30, 2018

Jun. 30, 2017

Jun. 30, 2018

Jun. 30, 2017

$ 1,449

$ 1,338

$ 3,575

$ 3,050

782

815

1,885

1,870

^[1]

(18)

(54)

(2)

Intersegment Eliminations [Member]

2,186

2,143

5,341

4,878

Electric Transmission and Distribution [Member]

(27)

(20)

(65)

(40)

Electric Transmission and Distribution [Member] | Intersegment Eliminations [Member]

^[2]

854

752

1,605

1,391

Natural Gas Distribution [Member] | Intersegment Eliminations [Member]

487

470

1,630

1,377

(8)

(7)

(18)

(16)

Energy Services [Member] | Intersegment Eliminations [Member]

841

918

2,098

2,103

Other Operations [Member]

(19)

(13)

(47)

(24)

Other Operations [Member] | Intersegment Eliminations [Member]

Reportable Subsegments [Member] | Intersegment Eliminations [Member]

^[3]

(8)

(7)

(18)

(16)

^[4]

(19)

(13)

(47)

(24)

Reportable Subsegments [Member] | Electric Transmission and Distribution [Member]

(27)

(20)

(65)

(40)

^[3]

860

758

1,621

1,402

^[3]

(4)

^[1],[3]

(6)

(12)

Reportable Subsegments [Member] | Natural Gas Distribution [Member]

^[3]

854

752

1,605

1,391

^[3]

509

463

1,695

1,388

^[3]

^[1],[3]

(14)

(47)

Reportable Subsegments [Member] | Energy Services [Member]

^[3]

487

470

1,630

1,377

^[4]

116

256

258

^[4]

782

815

1,889

1,869

^[1],[4]

Reportable Subsegments [Member] | Other Operations [Member]

^[4]

841

918

2,098

2,103

^[4]

^[4]

^[1],[4]

^[4]

Houston Electric [Member] | Reportable Subsegments [Member] | Electric Transmission and Distribution [Member]

854

752

1,609

1,390

860

758

1,621

1,402

^[1]

(6)

(12)

854

752

1,609

1,390

587

579

1,951

1,646

782

815

1,889

1,869

^[1]

(14)

(47)

CERC Corp [Member] | Intersegment Eliminations [Member]

1,328

1,387

3,728

3,480

CERC Corp [Member] | Natural Gas Distribution [Member]

(27)

(20)

(65)

(40)

CERC Corp [Member] | Natural Gas Distribution [Member] | Intersegment Eliminations [Member]

487

470

1,630

1,377

CERC Corp [Member] | Energy Services [Member]

(8)

(7)

(18)

(16)

CERC Corp [Member] | Energy Services [Member] | Intersegment Eliminations [Member]

841

918

2,098

2,103

CERC Corp [Member] | Other Operations [Member]

(19)

(13)

(47)

(24)

CERC Corp [Member] | Other Operations [Member] | Intersegment Eliminations [Member]

(1)

CERC Corp [Member] | Reportable Subsegments [Member] | Intersegment Eliminations [Member]

^[3]

(8)

(7)

(18)

(16)

^[4]

(19)

(13)

(47)

(24)

CERC Corp [Member] | Reportable Subsegments [Member] | Natural Gas Distribution [Member]

(27)

(20)

(65)

(40)

^[3]

509

463

1,695

1,388

^[3]

^[1],[3]

(14)

(47)

CERC Corp [Member] | Reportable Subsegments [Member] | Energy Services [Member]

^[3]

487

470

1,630

1,377

^[4]

116

256

258

^[4]

782

815

1,889

1,869

^[1],[4]

CERC Corp [Member] | Reportable Subsegments [Member] | Other Operations [Member]

^[4]

841

918

2,098

2,103

^[4]

^[4]

^[1],[4]

(1)

Defined Benefit Plan, Change in Accumulated Comprehensive Loss [Roll Forward]

^[4]

$ 0

$ (1)

$ 0

[1]	Primarily consists of income from ARPs and leases. ARPs are contracts between the utility and its regulators, not between the utility and a customer. The Registrants recognize ARP revenue as other revenues when the regulator-specified conditions for recognition have been met. Upon recovery of ARP revenue through incorporation in rates charged for utility service to customers, ARP revenue is reversed and recorded as revenue from contracts with customers. The recognition of ARP revenues and the reversal of ARP revenues upon recovery through rates charged for utility service may not occur in the same period.
[2]	CenterPoint Energy’s and Houston Electric’s Electric Transmission & Distribution revenues from major customers are as follows:
[3]	Reflected in Utility revenues in the Condensed Statements of Consolidated Income.
[4]	Reflected in Non-utility revenues in the Condensed Statements of Consolidated Income.

Employee Benefit Plans (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

Jun. 30, 2018

Jun. 30, 2017

Jun. 30, 2018

Jun. 30, 2017

Beginning Balance

$ (65)

$ (71)

$ (66)

$ (72)

Amounts reclassified from accumulated other comprehensive loss:

Prior service cost (1)

^[1]

Actuarial losses (1)

^[1]

Tax expense

(1)

(2)

Net current period other comprehensive income

Ending Balance

(63)

(70)

(63)

(70)

Pension Benefits [Member]

Other Postretirement Benefits Plan [Member]

Operation and maintenance expense [Member] | Pension Benefits [Member]

Operation and maintenance expense [Member] | Other Postretirement Benefits Plan [Member]

^[2]

Other, net [Member] | Pension Benefits [Member]

^[2]

^[3]

^[3]

(26)

(24)

(53)

(48)

Amortization of net loss (2)

^[3]

^[3]

Other, net [Member] | Other Postretirement Benefits Plan [Member]

^[3]

^[3]

(2)

(3)

Houston Electric [Member] | Other Postretirement Benefits Plan [Member]

^[3]

(1)

(2)

(1)

Houston Electric [Member] | Operation and maintenance expense [Member] | Other Postretirement Benefits Plan [Member]

Houston Electric [Member] | Other, net [Member] | Other Postretirement Benefits Plan [Member]

^[2]

^[3]

^[3]

(1)

(2)

CERC Corp [Member] | Other Postretirement Benefits Plan [Member]

^[3]

(2)

(1)

(3)

(2)

CERC Corp [Member] | Operation and maintenance expense [Member] | Other Postretirement Benefits Plan [Member]

CERC Corp [Member] | Other, net [Member] | Other Postretirement Benefits Plan [Member]

^[2]

^[3]

^[3]

(1)

Securitized regulatory assets

^[3]

$ 1

[1]	These accumulated other comprehensive components are included in the computation of net periodic cost.
[2]	Included in Operation and maintenance expense in the Registrants’ Condensed Statements of Consolidated Income.
[3]	Included in Other, net in the Registrants’ Condensed Statements of Consolidated Income.

Regulatory Accounting (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

Jun. 30, 2018

Jun. 30, 2017

Jun. 30, 2018

Jun. 30, 2017

Dec. 31, 2017

$ 1,293

$ 1,590

Unrecognized equity return (2)

^[1]

(242)

(287)

Unamortized loss on reacquired debt

2,067

2,347

2,122

2,477

Total regulatory liabilities

2,521

2,464

2,564

2,488

Total regulatory assets and liabilities, net

(442)

(11)

Securitized regulatory assets

1,293

1,590

Unrecognized equity return (2)

^[1]

(242)

(287)

Unamortized loss on reacquired debt

1,321

1,570

1,321

1,570

Total regulatory liabilities

1,265

1,263

1,271

1,285

Total regulatory assets and liabilities, net

285

Amount of allowed equity return on the true-up balance that was recognized in the period

$ 10

$ 17

Securitized regulatory assets

Unrecognized equity return (2)

^[1]

Unamortized loss on reacquired debt

173

181

228

311

Total regulatory liabilities

1,256

1,201

1,293

1,203

Total regulatory assets and liabilities, net

(1,065)

(892)

Hurricane Harvey [Member]

Hurricane Harvey [Member] | Houston Electric [Member]

^[2]

Hurricane Harvey [Member] | CERC Corp [Member]

^[2]

Prepaid expenses and other current assets [Member]

^[2]

Current regulatory assets (1)

^[3]

130

Prepaid expenses and other current assets [Member] | Houston Electric [Member]

Current regulatory assets (1)

^[3]

Prepaid expenses and other current assets [Member] | CERC Corp [Member]

Current regulatory assets (1)

^[3]

130

Other current liabilities [Member]

Current regulatory liabilities (7)

^[4]

Other current liabilities [Member] | Houston Electric [Member]

Current regulatory liabilities (7)

^[4]

Other current liabilities [Member] | CERC Corp [Member]

Current regulatory liabilities (7)

^[4]

Pension and Other Postretirement Plans Costs [Member]

Pension and Other Postretirement Plans Costs [Member] | Houston Electric [Member]

^[5]

623

646

Pension and Other Postretirement Plans Costs [Member] | CERC Corp [Member]

^[5]

Amounts related to TCJA [Member]

^[5]

^[6]

^[6]

Other Regulatory Assets (Liabilities) [Member]

^[6]

Other Regulatory Assets (Liabilities) [Member] | Houston Electric [Member]

^[7]

210

211

Other Regulatory Assets (Liabilities) [Member] | CERC Corp [Member]

^[7]

Amounts related to TCJA [Member]

^[7]

133

140

^[6]

1,389

1,354

^[6]

885

862

^[6]

504

492

Removal Costs [Member]

Removal Costs [Member] | Houston Electric [Member]

885

878

Removal Costs [Member] | CERC Corp [Member]

279

285

Other Regulatory Assets (Liabilities) [Member]

606

593

Other Regulatory Assets (Liabilities) [Member] | Houston Electric [Member]

247

232

Other Regulatory Assets (Liabilities) [Member] | CERC Corp [Member]

101

116

Natural Gas Distribution [Member] | Pension and Other Postretirement Plans Costs [Member]

146

116

Remaining amounts of regulatory assets for which no return on investment during recovery period is provided

$ 5

$ 7

[1]	The unrecognized equity return will be recognized as it is recovered in rates through 2024. During the three months ended June 30, 2018 and 2017, CenterPoint Energy and Houston Electric recognized approximately $24 million and $10 million, respectively, of the allowed equity return. During the six months ended June 30, 2018 and 2017, CenterPoint Energy and Houston Electric recognized approximately $45 million and $17 million, respectively, of the allowed equity return. The timing of CenterPoint Energy’s and Houston Electric’s recognition of the equity return will vary each period based on amounts actually collected during the period. The actual amounts recognized are adjusted at least annually to correct any over-collections or under-collections during the preceding 12 months.
[2]	The Registrants are not earning a return on Hurricane Harvey restoration costs.
[3]	Current regulatory assets are included in Prepaid expenses and other current assets in the Registrants’ Condensed Consolidated Balance Sheets.
[4]	Current regulatory liabilities are included in Other current liabilities in the Registrants’ Condensed Consolidated Balance Sheets.
[5]	Includes a portion of NGD’s actuarially determined pension and other postemployment expense in excess of the amount being recovered through rates that is being deferred for rate making purposes, of which $5 million and $7 million as of June 30, 2018 and December 31, 2017, respectively, were not earning a return.
[6]	The EDIT and deferred revenues will be recovered or refunded to customers as required by tax and regulatory authorities.
[7]	Other long-term regulatory assets that are not earning a return were not material as of June 30, 2018 and December 31, 2017.

Derivative Instruments Derivatives and hedging (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

Jun. 30, 2018

Jun. 30, 2017

Jun. 30, 2018

Jun. 30, 2017

Mar. 26, 2018

Feb. 28, 2018

Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member]

Weather hedges term

10 years

2018 to 2019 [Member] | Natural Gas Distribution [Member]

^[1]

$ 0

$ (4)

$ 1

2018 to 2019 [Member] | Electric Transmission and Distribution [Member]

2018 to 2019 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Electric Transmission and Distribution [Member]

2017 to 2018 [Member] | Natural Gas Distribution [Member]

2017 to 2018 [Member] | Electric Transmission and Distribution [Member]

2017 to 2018 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Electric Transmission and Distribution [Member]

2016 to 2017 [Member] | Electric Transmission and Distribution [Member]

(4)

2016 to 2017 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Electric Transmission and Distribution [Member]

Houston Electric [Member] | January thru February [Member] | Treasury Lock [Member]

Aggregate notional amount

200

Effective portion of realized gains (losses)

CERC Corp [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member]

CERC Corp [Member] | 2018 to 2019 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Natural Gas Distribution [Member]

^[1]

CERC Corp [Member] | 2017 to 2018 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Natural Gas Distribution [Member]

CERC Corp [Member] | March [Member] | Treasury Lock [Member]

$ 0

Aggregate notional amount

$ 450

450

Effective portion of realized gains (losses)

$ (1)

General Mortgage Bonds Due 2048 [Member] | Houston Electric [Member]

Senior Notes [Member] | CERC Corp [Member]

$ 400

$ 600

[1]	Weather hedge gains (losses) are recorded in Revenues in the Condensed Statements of Consolidated Income.

Derivative Instruments Derivative Fair Values (Details)
$ in Millions

3 Months Ended

6 Months Ended

12 Months Ended

Jun. 30, 2018

USD ($)

Jun. 30, 2017

USD ($)

Jun. 30, 2018

USD ($)

Bcf

Jun. 30, 2017

USD ($)

Dec. 31, 2017

USD ($)

Bcf

$ 160

$ 218

Gain (loss) on derivative instruments not designated as hedging instruments

751

775

(252)

$ 14

(282)

$ 27

Aggregate fair value of derivatives containing material adverse change provisions in a net liability position

Fair value of collateral already posted

Additional collateral required to be posted if credit risk contingent features triggered

$ 2

Gains (Losses) in Non-utility natural gas expense [Member]

Change in unrealized gain (loss) on hedged item in fair value hedge

(12)

(4)

(14)

Gain (loss) on fair value hedges recognized in earnings

^[1]

(1)

$ (1)

(2)

Energy Related Derivative [Member]

Derivative gross volume notional amount (in Bcf) | Bcf

1,862

1,795

Net amount presented in the consolidated balance sheets

^[2]

$ 82

$ 130

Gross Amounts Offset in the Consolidated Balance Sheets

^[3]

111

Change in unrealized gain (loss) on fair value hedging instruments

^[3]

165

(25)

(55)

Derivative Asset

^[2]

110

^[3]

(15)

(9)

Derivative Asset

^[2]

^[3]

(69)

(83)

Derivative Liability

^[2]

(26)

(20)

^[3]

(41)

(24)

Derivative Liability

^[2]

(12)

$ (12)

$ (4)

Derivative gross volume notional amount (in Bcf) | Bcf

268

224

IDS Derivative [Member] | Gains (losses) in Other Income (Expense) [Member]

Gain (loss) on derivative instruments not designated as hedging instruments

(254)

(13)

$ (272)

(23)

IDS Derivative [Member] | Not Designated as Hedging Instrument [Member] | Current Liabilities [Member]

$ 0

641

668

160

218

Gain (loss) on derivative instruments not designated as hedging instruments

110

107

(10)

CERC Corp [Member] | Energy Related Derivative [Member] | Gains (Losses) in Non-utility revenues [Member]

Gain (loss) on derivative instruments not designated as hedging instruments

132

CERC Corp [Member] | Energy Related Derivative [Member] | Gains (Losses) in Non-utility natural gas expense [Member]

Gain (loss) on derivative instruments not designated as hedging instruments

(9)

$ (9)

(78)

$ (82)

CERC Corp [Member] | Energy Related Derivative [Member] | Designated as Fair Value Hedge [Member] | Current Liabilities [Member]

^[4],[5],[6]

CERC Corp [Member] | Energy Related Derivative [Member] | Not Designated as Hedging Instrument [Member] | Current Assets [Member]

^[4],[5],[6]

^[4],[5],[6]

114

CERC Corp [Member] | Energy Related Derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]

^[4],[5],[6]

^[4],[5],[6]

CERC Corp [Member] | Energy Related Derivative [Member] | Not Designated as Hedging Instrument [Member] | Current Liabilities [Member]

^[4],[5],[6]

^[4],[5],[6]

CERC Corp [Member] | Energy Related Derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Liabilities [Member]

^[4],[5],[6]

^[4],[5],[6]

Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]

^[4],[5],[6]

$ 41

$ 24

[1]	Hedge ineffectiveness results from the basis ineffectiveness discussed above, and excludes the impact to natural gas expense from timing ineffectiveness. Timing ineffectiveness arises due to changes in the difference between the spot price and the futures price, as well as the difference between the timing of the settlement of the futures and the valuation of the underlying physical commodity. As the commodity contract nears the settlement date, spot-to-forward price differences should converge, which should reduce or eliminate the impact of this ineffectiveness on natural gas expense.
[2]	The derivative assets and liabilities on the Condensed Consolidated Balance Sheets exclude accounts receivable or accounts payable that, should they exist, could be used as offsets to these balances in the event of a default.
[3]	Gross amounts recognized include some derivative assets and liabilities that are not subject to master netting arrangements.
[4]	Derivative Assets and Derivative Liabilities include no material amounts related to physical forward transactions with Enable.
[5]	Natural gas contracts are presented on a net basis in the Condensed Consolidated Balance Sheets as they are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets. The net of total non-trading natural gas derivative assets and liabilities was a $82 million asset and a $130 million asset as of June 30, 2018 and December 31, 2017, respectively, as shown on CenterPoint Energy’s and CERC’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above, impacted by collateral netting of $32 million and $19 million, respectively.
[6]	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 1,862 Bcf or a net 268 Bcf long position and 1,795 Bcf or a net 224 Bcf long position as of June 30, 2018 and December 31, 2017, respectively. Certain natural gas contracts hedge basis risk only and lack a fixed price exposure.

Fair Value Measurements (Details)

3 Months Ended

6 Months Ended

Jun. 30, 2018

USD ($)

Jun. 30, 2017

USD ($)

Jun. 30, 2018

USD ($)

Jun. 30, 2017

USD ($)

Dec. 31, 2017

USD ($)

Fair value amount of Level 1 to Level 2 assets transferred

$ 0

Fair value amount of Level 2 to Level 1 assets transferred

Fair value amount of Level 1 to Level 2 liabilities transferred

Fair value amount of Level 2 to Level 1 liabilities transferred

Assets

Total derivative assets, netting adjustment

^[1]

(40,000,000)

$ (64,000,000)

776,000,000

1,199,000,000

Total derivative liabilities, netting adjustment

^[1]

(72,000,000)

(83,000,000)

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]

680,000,000

692,000,000

Beginning balance

(662,000,000)

$ (700,000,000)

(622,000,000)

$ (704,000,000)

Total gains (losses)

(11,000,000)

(6,000,000)

(16,000,000)

Total settlements

44,000,000

11,000,000

(4,000,000)

Transfers into Level 3

1,000,000

2,000,000

Transfers out of Level 3

(7,000,000)

(2,000,000)

(6,000,000)

Ending balance (1)

^[2]

(628,000,000)

(712,000,000)

(628,000,000)

(712,000,000)

The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the reporting date:

(9,000,000)

(23,000,000)

(2,000,000)

Carrying Amount [Member]

^[3]

8,256,000,000

8,679,000,000

Fair Value [Member]

Natural gas derivatives [Member]

^[3]

8,470,000,000

9,220,000,000

Assets

Derivative fair value offsets, net

32,000,000

19,000,000

Fair Value, Inputs, Level 1 [Member]

Assets

656,000,000

1,045,000,000

Fair Value, Inputs, Level 2 [Member]

1,000,000

Assets

142,000,000

161,000,000

Fair Value, Inputs, Level 3 [Member]

105,000,000

96,000,000

Assets

18,000,000

57,000,000

Fair Value, Inputs, Level 3 [Member] | Forward Contracts [Member] | Minimum [Member]

646,000,000

$ 646,000,000

679,000,000

Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]

Fair value inputs (price per MMBtu)

1.04

Fair Value, Inputs, Level 3 [Member] | Forward Contracts [Member] | Maximum [Member]

Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]

Fair value inputs (price per MMBtu)

3.31

Fair Value, Measurements, Recurring [Member]

Assets

586,000,000

$ 586,000,000

963,000,000

^[4]

70,000,000

68,000,000

14,000,000

Fair Value, Measurements, Recurring [Member] | IDS Derivative [Member]

1,000,000

Derivative liabilities, netting adjustment

^[1]

Derivative liabilities

641,000,000

668,000,000

Fair Value, Measurements, Recurring [Member] | Natural gas derivatives [Member]

Assets

Derivative asset, netting adjustment

^[1],[5]

(40,000,000)

(64,000,000)

Derivative assets

^[5]

120,000,000

154,000,000

Derivative liabilities, netting adjustment

^[1],[5]

(72,000,000)

(83,000,000)

Derivative liabilities

^[5]

38,000,000

24,000,000

Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]

Assets

586,000,000

963,000,000

^[4]

70,000,000

68,000,000

14,000,000

Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | IDS Derivative [Member]

1,000,000

Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Natural gas derivatives [Member]

Assets

^[5]

Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]

^[5]

Assets

^[4]

Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | IDS Derivative [Member]

Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Natural gas derivatives [Member]

Assets

^[5]

142,000,000

161,000,000

Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]

^[5]

105,000,000

96,000,000

Assets

^[4]

Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | IDS Derivative [Member]

Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Natural gas derivatives [Member]

641,000,000

668,000,000

Assets

^[5]

18,000,000

57,000,000

^[5]

5,000,000

11,000,000

Total derivative assets, netting adjustment

Assets

^[1]

(40,000,000)

(64,000,000)

133,000,000

182,000,000

Total derivative liabilities, netting adjustment

^[1]

(72,000,000)

(83,000,000)

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]

39,000,000

24,000,000

Beginning balance

12,000,000

27,000,000

46,000,000

13,000,000

Total gains (losses)

1,000,000

7,000,000

3,000,000

23,000,000

Total settlements

(1,000,000)

(35,000,000)

(4,000,000)

Transfers into Level 3

1,000,000

2,000,000

Transfers out of Level 3

(7,000,000)

(2,000,000)

(6,000,000)

Ending balance (1)

^[2]

13,000,000

28,000,000

13,000,000

28,000,000

The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the reporting date:

3,000,000

$ 4,000,000

(4,000,000)

$ 21,000,000

CERC Corp [Member] | Carrying Amount [Member]

CERC Corp [Member] | Fair Value [Member]

2,722,000,000

2,457,000,000

CERC Corp [Member] | Fair Value, Inputs, Level 1 [Member]

2,876,000,000

2,708,000,000

Assets

13,000,000

28,000,000

CERC Corp [Member] | Fair Value, Inputs, Level 2 [Member]

1,000,000

Assets

142,000,000

161,000,000

CERC Corp [Member] | Fair Value, Inputs, Level 3 [Member]

105,000,000

96,000,000

Assets

18,000,000

57,000,000

CERC Corp [Member] | Fair Value, Measurements, Recurring [Member]

5,000,000

11,000,000

Assets

2,000,000

3,000,000

^[4]

11,000,000

14,000,000

CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Natural gas derivatives [Member]

1,000,000

Assets

Derivative asset, netting adjustment

^[1],[5]

(40,000,000)

(64,000,000)

Derivative assets

^[5]

120,000,000

154,000,000

Derivative liabilities, netting adjustment

^[1],[5]

(72,000,000)

(83,000,000)

Derivative liabilities

^[5]

38,000,000

24,000,000

CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]

Assets

2,000,000

3,000,000

^[4]

11,000,000

14,000,000

CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Natural gas derivatives [Member]

1,000,000

Assets

^[5]

CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]

^[5]

Assets

^[4]

CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Natural gas derivatives [Member]

Assets

^[5]

142,000,000

161,000,000

CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]

^[5]

105,000,000

96,000,000

Assets

^[4]

CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Natural gas derivatives [Member]

Assets

^[5]

18,000,000

57,000,000

^[5]

5,000,000

11,000,000

Total derivative assets, netting adjustment

Assets

Houston Electric [Member] | Carrying Amount [Member]

52,000,000

51,000,000

Houston Electric [Member] | Fair Value [Member]

^[3]

4,919,000,000

4,753,000,000

Houston Electric [Member] | Fair Value, Inputs, Level 1 [Member]

^[3]

4,991,000,000

5,034,000,000

Assets

Houston Electric [Member] | Fair Value, Inputs, Level 2 [Member]

52,000,000

51,000,000

Assets

Houston Electric [Member] | Fair Value, Inputs, Level 3 [Member]

Assets

Houston Electric [Member] | Fair Value, Measurements, Recurring [Member]

Assets

Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]

^[4]

52,000,000

51,000,000

Assets

Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]

^[4]

52,000,000

51,000,000

Assets

Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]

^[4]

Assets

^[4]

$ 0

[1]	Amounts represent the impact of legally enforceable master netting arrangements that allow CenterPoint Energy and CERC to settle positive and negative positions and also include cash collateral of $32 million and $19 million as of June 30, 2018 and December 31, 2017, respectively, posted with the same counterparties.
[2]	CenterPoint Energy and CERC did not have significant Level 3 sales or purchases during either of the three or six months ended June 30, 2018 or 2017.
[3]	Includes Securitization Bond debt.
[4]	Amounts are included in Prepaid expenses and other current assets in the Condensed Consolidated Balance Sheets.
[5]	Natural gas derivatives include no material amounts related to physical forward transactions with Enable.

Unconsolidated Affiliate (CenterPoint Energy and CERC) (Details) - USD ($)
$ / shares in Units, $ in Millions

3 Months Ended

6 Months Ended

Jun. 30, 2018

Jun. 30, 2017

Jun. 30, 2018

Jun. 30, 2017

Dec. 31, 2017

Preferred units – unconsolidated affiliate

$ 363

Percentage of sales that trigger right of first refusal

5.00%

Total distributions received from Enable

$ 84

$ 167

Equity Method Investment, Summarized Financial Information, Gross Profit (Loss) [Abstract]

CenterPoint Energy’s and CERC’s equity in earnings, net

127

131

Equity Method Investment, Difference Between Carrying Amount and Underlying Equity [Abstract]

CenterPoint Energy’s and CERC’s equity method investment in Enable

2,451

2,472

Total distributions received from Enable

149

Equity Method Investment, Summarized Financial Information, Gross Profit (Loss) [Abstract]

CenterPoint Energy’s and CERC’s equity in earnings, net

127

131

Equity Method Investment, Difference Between Carrying Amount and Underlying Equity [Abstract]

CenterPoint Energy’s and CERC’s equity method investment in Enable

$ 2,451

2,472

OGE [Member]

Percentage of sales that trigger right of first refusal

5.00%

Enable Midstream Partners [Member]

Ownership percentage of equity method investment

54.00%

Equity Method Investment, Summarized Financial Information, Gross Profit (Loss) [Abstract]

Operating revenues

$ 805

626

$ 1,553

1,292

Cost of sales, excluding depreciation and amortization

444

279

819

587

Operating income

126

122

265

262

Net income attributable to Enable

191

197

CenterPoint Energy’s and CERC’s interest

103

107

Basis difference amortization (1)

^[1]

CenterPoint Energy’s and CERC’s equity in earnings, net

$ 127

131

Basis difference amortization period

31 years

Equity Method Investment, Summarized Financial Information, Assets and Liabilities [Abstract]

Current assets

432

$ 432

416

Non-current assets

11,360

11,177

Current liabilities

1,258

1,279

Non-current liabilities

2,963

2,660

Non-controlling interest

Preferred equity

362

Enable partners’ equity

7,198

7,280

Equity Method Investment, Difference Between Carrying Amount and Underlying Equity [Abstract]

CenterPoint Energy’s and CERC’s ownership interest in Enable partners’ equity

3,887

3,935

CenterPoint Energy’s and CERC’s basis difference

(1,436)

(1,463)

CenterPoint Energy’s and CERC’s equity method investment in Enable

2,451

2,472

Enable Midstream Partners [Member] | Common Units [Member]

Distributions received from Enable equity method investment

149

Enable Midstream Partners [Member] | Series A Preferred Units [Member]

Distributions received from Enable cost method investment

$ 9

$ 18

Enable Midstream Partners [Member] | CERC Corp [Member]

Ownership percentage of equity method investment

^[2]

54.00%

Enable Midstream Partners [Member]

Limited partner ownership interest

^[2]

100.00%

Maximum incentive distribution right

50.00%

Enable Midstream Partners [Member] | CERC Corp [Member]

Management rights ownership percentage

50.00%

Incentive distribution right

40.00%

Enable Midstream Partners [Member] | OGE [Member]

Limited partner ownership interest

^[2]

25.60%

Management rights ownership percentage

50.00%

Incentive distribution right

60.00%

Enable Midstream Partners [Member] | Public unitholders [Member]

Limited partner ownership interest

^[2]

20.40%

Enable Midstream Partners [Member] | Minimum [Member]

Incentive distribution per unit

$ 0.2875

Enable Midstream Partners [Member] | Maximum [Member]

Incentive distribution per unit

$ 0.330625

Common Units [Member] | Enable Midstream Partners [Member] | CERC Corp [Member]

Common Units [Member] | Enable Midstream Partners [Member]

233,856,623

Common Units [Member] | Enable Midstream Partners [Member] | OGE [Member]

433,064,636

Common Units [Member] | Enable Midstream Partners [Member] | Public unitholders [Member]

110,982,805

Series A Preferred Units [Member] | Enable Midstream Partners [Member]

88,225,208

Transitional Service [Member] | Enable Midstream Partners [Member]

Preferred Units Held

^[3]

14,520,000

Transactions with Enable [Abstract]

Reimbursement of transition services (1)

^[4]

$ 1

$ 3

Accounts receivable for amounts billed for transition services

Natural Gas Expenses [Member] | Enable Midstream Partners [Member]

Transactions with Enable [Abstract]

Natural gas expenses, including transportation and storage costs

$ 24

$ 57

Accounts payable for natural gas purchases from Enable

$ 8

$ 13

[1]	Equity in earnings of unconsolidated affiliate includes CenterPoint Energy’s and CERC’s share of Enable’s earnings adjusted for the amortization of the basis difference of CenterPoint Energy’s and CERC’s original investment in Enable and their underlying equity in Enable’s net assets. The basis difference is amortized over approximately 31 years, the average life of the assets to which the basis difference is attributed.
[2]	Excluding the Series A Preferred Units owned by CenterPoint Energy.
[3]	The carrying amount of the Series A Preferred Units, reflected as Preferred units - unconsolidated affiliate on CenterPoint Energy’s Condensed Consolidated Balance Sheets, was $363 million as of both June 30, 2018 and December 31, 2017. No impairment charges or adjustment due to observable price changes were made during the current or prior reporting periods. See Note 2 for further discussion.
[4]	Represents amounts billed under the Transition Agreements for certain support services provided to Enable. Actual transition services costs are recorded net of reimbursement.

Goodwill and Other Intangibles (CenterPoint Energy and CERC) (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

12 Months Ended

Jun. 30, 2018

Jun. 30, 2017

Jun. 30, 2018

Jun. 30, 2017

Dec. 31, 2017

$ 867

105

(36)

(31)

Amortization expense of intangible assets

$ 1

$ 3

746

Accumulated goodwill impairment charge recorded in 2012

^[1]

110

252

Other Operations [Member]

Customer Relationships [Member]

$ 11

Intangible asset useful lives

15 years

$ 86

(25)

(21)

Noncompete Agreements [Member]

$ 61

$ 65

Intangible asset useful lives

4 years

$ 4

(2)

Other Intangible Assets [Member]

(9)

(8)

Cash paid per share exchanged | $ / shares

$ 6

$ 7

[1]	Amount presented is net of the accumulated goodwill impairment charge of $252 million recorded in 2012.

Indexed Debt Securities (ZENS) and Securities Related to ZENS (CenterPoint Energy) (Details)
$ / shares in Units, $ in Millions

6 Months Ended

Jul. 17, 2018

USD ($)

Jun. 30, 2018

USD ($)

$ / shares

Jun. 30, 2017

USD ($)

Jun. 14, 2018

$ / shares

Jan. 31, 2018

$ / shares

Dec. 31, 2017

USD ($)

Nov. 26, 2017

$ / shares

$ 72.00

Distribution To ZENS holders

$ 16

$ 0

Due to ZENS note holders

382

$ 0

Subordinated Debt ZENS [Member]

Subordinated note cash exchangeable percentage of fair value

1,000

Outstanding debt balance

$ 828

95.00%

Contingent principal amount outstanding

$ 484

AT&T Common [Member]

AT&T Common [Member] | Subordinated Debt ZENS [Member]

10,212,945

Number of shares referenced in exchangeable subordinated note | shares

0.7185

Charter Common [Member]

Charter Common [Member] | Subordinated Debt ZENS [Member]

872,503

Number of shares referenced in exchangeable subordinated note | shares

0.061382

Time Common [Member]

ZENS early exchange ratio

888,392

100.00%

Time Common [Member] | Subordinated Debt ZENS [Member]

Number of shares referenced in exchangeable subordinated note | shares

0.0625

TW Common [Member]

TW Common [Member] | Subordinated Debt ZENS [Member]

7,107,130

Number of shares referenced in exchangeable subordinated note | shares

0.5

AT&T To Acquire Time Warner [Member]

Due to ZENS note holders

^[1]

$ 382

Indexed debt – reduction

(95)

Indexed debt securities derivative – reduction

(45)

Loss on indexed debt securities

242

AT&T To Acquire Time Warner [Member] | AT&T Common [Member]

Cash paid per share exchanged | $ / shares

$ 53.75

Fractional shares exchanged for each TW Common share held | shares

1.437

Cash proceeds received for shares exchanged

382

Total AT&T shares received in exchange for TW Common shares held | shares

10,212,945

Meredith to acquire Time [Member]

Distribution To ZENS holders

Indexed debt – reduction

(4)

Indexed debt securities derivative – reduction

(1)

Loss on indexed debt securities

Meredith to acquire Time [Member] | Time Common [Member]

Cash paid per share exchanged | $ / shares

$ 18.50

Cash proceeds received for shares exchanged

$ 16

Subsequent Event [Member]

Distribution To ZENS holders

$ 382

[1]	Cash of approximately $382 million was paid to ZENS note holders in July 2018.

Short-Term Borrowings and Long-term Debt (Details)

6 Months Ended

Mar. 26, 2018

USD ($)

Feb. 28, 2018

USD ($)

Jun. 30, 2018

USD ($)

Dec. 31, 2017

USD ($)

Short-term Debt [Line Items]

Short-term borrowings

$ 0

$ 39,000,000

2,900,000,000

Parent Company [Member]

Temporary increased line of credit facility, maximum borrowing capacity

1,700,000,000

^[1]

1,700,000,000

3,300,000,000

General mortgage bonds used as collateral

300,000,000

118,000,000

Short-term Debt [Line Items]

Short-term borrowings

39,000,000

Revolving Credit Facility [Member]

900,000,000

Revolving Credit Facility [Member] | Parent Company [Member]

Revolving Credit Facility [Member] | Houston Electric [Member]

^[2]

Revolving Credit Facility [Member] | CERC Corp [Member]

Line of Credit [Member] | Parent Company [Member]

$ 0

Percentage on limitation of debt to total capitalization under covenant

65.00%

Percentage on limitation of debt to total capitalization under covenant amended (in hundredths)

70.00%

Ratio of indebtedness to net capital

^[3]

0.521

System restoration costs threshold for increase in permitted debt to EBITDA covenant ratio

$ 100,000,000

Consecutive period for system restoration costs to exceed $100 million (in months)

Line of Credit [Member] | Parent Company [Member] | London Interbank Offered Rate (LIBOR) [Member]

Line of Credit [Member] | Houston Electric [Member]

Basis spread on LIBOR

^[4]

1.25%

Percentage on limitation of debt to total capitalization under covenant

^[5]

65.00%

Ratio of indebtedness to net capital

^[3]

0.507

Line of Credit [Member] | Houston Electric [Member] | London Interbank Offered Rate (LIBOR) [Member]

Line of Credit [Member] | CERC Corp [Member]

Basis spread on LIBOR

^[4]

1.125%

Percentage on limitation of debt to total capitalization under covenant

65.00%

Ratio of indebtedness to net capital

^[3]

0.378

Line of Credit [Member] | CERC Corp [Member] | London Interbank Offered Rate (LIBOR) [Member]

Letter of Credit [Member]

Basis spread on LIBOR

^[4]

1.25%

Letter of Credit [Member] | Parent Company [Member]

$ 11,000,000

11,000,000

Letter of Credit [Member] | Houston Electric [Member]

^[2]

6,000,000

Letter of Credit [Member] | CERC Corp [Member]

4,000,000

Commercial Paper [Member]

1,000,000

Commercial Paper [Member] | Parent Company [Member]

565,000,000

1,753,000,000

Weighted average interest rate of debt

^[2]

$ 0

$ 855,000,000

^[2]

0.00%

1.88%

Commercial Paper [Member] | Houston Electric [Member]

Commercial Paper [Member] | CERC Corp [Member]

$ 0

Weighted average interest rate of debt

$ 565,000,000

$ 898,000,000

2.37%

1.72%

General Mortgage Bonds Due 2048 [Member] | Houston Electric [Member]

Debt Instruments [Abstract]

Interest rate of debt issued

$ 400,000,000

3.95%

Maturity date of debt issued

Mar. 01, 2048

Senior Notes Due 2023 [Member] | CERC Corp [Member]

Debt Instruments [Abstract]

Interest rate of debt issued

$ 300,000,000

3.55%

Maturity date of debt issued

Apr. 01, 2023

Senior Notes Due 2028 [Member]

Debt Instruments [Abstract]

Interest rate of debt issued

$ 300,000,000

4.00%

Maturity date of debt issued

Apr. 01, 2028

Product Financing Arrangement [Member]

Short-term Debt [Line Items]

Short-term borrowings

$ 0

$ 39,000,000

Merger Agreement with Vectren [Member] | Parent Company [Member]

Temporary increased line of credit facility, maximum borrowing capacity

$ 3,300,000,000

Merger Agreement with Vectren [Member] | Line of Credit [Member] | Parent Company [Member]

Percentage on limitation of debt to total capitalization under covenant amended (in hundredths)

^[5],[6]

75.00%

[1]	Pursuant to the amendment entered into in May 2018, the aggregate commitments under the CenterPoint Energy revolving credit facility will increase to $3.3 billion upon the satisfaction of certain conditions described above.
[2]	Pursuant to the amendment entered into in May 2018, the aggregate commitments under the CenterPoint Energy revolving credit facility will increase to $3.3 billion upon the satisfaction of certain conditions described above.
[3]	As defined in the revolving credit facility agreement, excluding Securitization Bonds.
[4]	Based on current credit ratings.
[5]	For CenterPoint Energy (whenever its financial covenant limit is 65%) and Houston Electric, the financial covenant limit will temporarily increase from 65% to 70% if Houston Electric experiences damage from a natural disaster in its service territory and CenterPoint Energy certifies to the administrative agent that Houston Electric has incurred system restoration costs reasonably likely to exceed $100 million in a consecutive 12-month period, all or part of which Houston Electric intends to seek to recover through securitization financing. Such temporary increase in the financial covenant would be in effect from the date CenterPoint Energy delivers its certification until the earliest to occur of (i) the completion of the securitization financing, (ii) the first anniversary of CenterPoint Energy’s certification or (iii) the revocation of such certification.
[6]	CenterPoint Energy’s financial covenant limit will return to 65% upon the earlier of (i) June 30, 2019 or (ii) the termination of all commitments in respect of the Bridge Facility without any borrowing thereunder.

Income Taxes (Details)	3 Months Ended		6 Months Ended
Income Taxes (Details)	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Effective income tax rate	15.00%	36.00%	27.00%	36.00%
Federal statutory income tax rate			21.00%	35.00%
Houston Electric [Member]
Effective income tax rate	21.00%	36.00%	22.00%	36.00%
CERC Corp [Member]
Effective income tax rate	22.00%	35.00%	22.00%	37.00%

Commitments and Contingencies (Details)	6 Months Ended
Commitments and Contingencies (Details)	Jun. 30, 2018 USD ($)
CERC Corp [Member] \| Minnesota Service Territory [Member]
Legal, Environmental and Other Matters
Liability recorded for remediation of Minnesota sites	$ 7,000,000
CERC Corp [Member] \| Minnesota Service Territory [Member] \| Minimum [Member]
Legal, Environmental and Other Matters
Estimated remediation costs for the Minnesota sites	$ 4,000,000
Years to resolve contingency	30 years
CERC Corp [Member] \| Minnesota Service Territory [Member] \| Maximum [Member]
Legal, Environmental and Other Matters
Estimated remediation costs for the Minnesota sites	$ 30,000,000
Years to resolve contingency	50 years
Natural Gas Supply Commitments [Member]
Natural Gas Supply Commitments
Remaining six months of 2018	$ 185,000,000
2019	264,000,000
2020	168,000,000
2021	82,000,000
2022	51,000,000
2023 and beyond	123,000,000
Minnehaha Academy Gas Explosion [Member]
Legal, Environmental and Other Matters
Contested amount of fines imposed	$ 200,000

Earnings Per Share (CenterPoint Energy) (Details) - USD ($)
$ / shares in Units, $ in Millions

3 Months Ended

6 Months Ended

Jun. 30, 2018

Jun. 30, 2017

Jun. 30, 2018

Jun. 30, 2017

Net income (loss)

$ (75)

$ 135

$ 90

$ 327

Basic weighted average shares outstanding

431,523,000

430,996,000

431,378,000

430,896,000

Plus: Incremental shares from assumed conversions:

Diluted weighted average shares

431,523,000

433,797,000

434,407,000

433,697,000

Basic earnings (loss) per share

Net income (loss)

$ (0.17)

$ 0.31

$ 0.21

$ 0.76

Diluted earnings (loss) per share

Net income (loss)

$ (0.17)

$ 0.31

$ 0.21

$ 0.75

Restricted Stock [Member]

Anti-dilutive shares excluded from computation of diluted earnings (loss) per share

3,029,000

Plus: Incremental shares from assumed conversions:

Restricted stock (1)

^[1]

2,801,000

3,029,000

2,801,000

[1]	3,029,000 incremental shares from assumed conversions of restricted stock have not been included in the computation of diluted earnings (loss) per share for the three months ended June 30, 2018 as their inclusion would be anti-dilutive.

Reportable Business Segments (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

Jun. 30, 2018

Jun. 30, 2017

Jun. 30, 2018

Jun. 30, 2017

Dec. 31, 2017

$ 2,186

$ 2,143

$ 5,341

$ 4,878

Equity in earnings from investment in Enable

187

240

438

531

127

131

22,108

$ 22,736

Electric Transmission and Distribution [Member]

2,122

2,477

^[1]

854

752

1,605

1,391

Electric Transmission and Distribution [Member] | Affiliates of NRG Energy, Inc. [Member]

181

171

296

257

Electric Transmission and Distribution [Member] | Affiliates of Vistra Energy Corp. [Member]

169

167

330

319

113

100

487

470

1,630

1,377

163

210

841

918

2,098

2,103

Midstream Investments [Member]

(11)

^[2]

Equity in earnings from investment in Enable

^[2]

127

131

Other Operations [Member]

Intersegment Eliminations [Member]

(16)

(10)

(27)

(20)

(65)

(40)

Intersegment Eliminations [Member] | Electric Transmission and Distribution [Member]

(841)

(654)

Intersegment Eliminations [Member] | Natural Gas Distribution [Member]

Intersegment Eliminations [Member] | Energy Services [Member]

(8)

(7)

(18)

(16)

Intersegment Eliminations [Member] | Midstream Investments [Member]

(19)

(13)

(47)

(24)

Intersegment Eliminations [Member] | Other Operations [Member]

^[2]

Operating Segments [Member] | Electric Transmission and Distribution [Member]

Operating Segments [Member] | Natural Gas Distribution [Member]

10,430

10,292

Operating Segments [Member] | Energy Services [Member]

6,501

6,608

Operating Segments [Member] | Midstream Investments [Member]

1,256

1,521

Operating Segments [Member] | Other Operations [Member]

2,451

2,472

Pension and Other Postretirement Plans Costs [Member] | Other Operations [Member]

^[3]

2,311

2,497

577

600

1,328

1,387

3,728

3,480

Equity in earnings from investment in Enable

153

258

127

131

9,642

10,112

CERC Corp [Member] | Natural Gas Distribution [Member]

228

311

487

470

1,630

1,377

CERC Corp [Member] | Energy Services [Member]

163

210

841

918

2,098

2,103

CERC Corp [Member] | Midstream Investments [Member]

(11)

^[2]

CERC Corp [Member] | Other Operations [Member]

^[2]

(1)

CERC Corp [Member] | Intersegment Eliminations [Member]

(3)

(27)

(20)

(65)

(40)

CERC Corp [Member] | Intersegment Eliminations [Member] | Natural Gas Distribution [Member]

(655)

(559)

CERC Corp [Member] | Intersegment Eliminations [Member] | Energy Services [Member]

(8)

(7)

(18)

(16)

CERC Corp [Member] | Intersegment Eliminations [Member] | Midstream Investments [Member]

(19)

(13)

(47)

(24)

CERC Corp [Member] | Intersegment Eliminations [Member] | Other Operations [Member]

^[2]

CERC Corp [Member] | Operating Segments [Member] | Natural Gas Distribution [Member]

$ 0

CERC Corp [Member] | Operating Segments [Member] | Energy Services [Member]

6,501

6,608

CERC Corp [Member] | Operating Segments [Member] | Midstream Investments [Member]

1,256

1,521

CERC Corp [Member] | Operating Segments [Member] | Other Operations [Member]

2,451

2,472

$ 89

$ 70

[1]	CenterPoint Energy’s and Houston Electric’s Electric Transmission & Distribution revenues from major customers are as follows:
[2]	CenterPoint Energy’s and CERC’s Midstream Investments’ equity earnings, net are as follows: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 (in millions)Enable $58 $59 $127 $131
[3]	Includes pension and other postemployment-related regulatory assets of $577 million and $600 million, respectively, as of June 30, 2018 and December 31, 2017.

Supplemental Disclosure of Cash Flow Information (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Interest, net of capitalized interest	$ 167	$ 182
Income taxes, net	88	11
Accounts payable related to capital expenditures	133	106
Cash and cash equivalents	328		$ 260
Total cash, cash equivalents and restricted cash shown in Condensed Statements of Consolidated Cash Flows	366	280	296	$ 381
Prepaid expenses and other current assets [Member]
Restricted cash	37		35
Other [Member]
Restricted cash	1		1
Houston Electric [Member]
Interest, net of capitalized interest	90	94
Income taxes, net	120	76
Accounts payable related to capital expenditures	75	75
Cash and cash equivalents	253		238
Total cash, cash equivalents and restricted cash shown in Condensed Statements of Consolidated Cash Flows	291	277	274	381
Houston Electric [Member] \| Prepaid expenses and other current assets [Member]
Restricted cash	37		35
Houston Electric [Member] \| Other [Member]
Restricted cash	1		1
CERC Corp [Member]
Interest, net of capitalized interest	50	56
Income taxes, net	3	3
Accounts payable related to capital expenditures	69	44
Cash and cash equivalents	$ 1	$ 1	$ 12	$ 1

Related Party Transactions (Houston Electric and CERC) (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

Jun. 30, 2018

Jun. 30, 2017

Jun. 30, 2018

Jun. 30, 2017

Dec. 31, 2017

Houston Electric [Member] | Operation and maintenance expense [Member]

Dividends paid

$ 31

$ 10

$ 63

$ 42

Net affiliate service charges (billings)

(3)

(4)

(5)

Houston Electric [Member] | CenterPoint Energy [Member] | Operation and maintenance expense [Member]

Corporate service charges