View Filing Data

$ 62

^[1],[2]

$ 62

^[1],[2]

$ 80

^[3],[4]

Derivative gross volumes (Bcf)

358

^[1],[2]

$ 358

^[1],[2]

$ 411

^[3],[4]

593

626

Net long position (Bcf)

110

Amount of net long position constituted by basis swaps (Bcf)

Amount of net long position comprised of price stabilization activities of the Natural Gas Distribution business segment (Bcf)

Total non-trading derivative assets and liabilities net of collateral

$ 1

$ (15)

Collateral netting

Derivative Instruments, Gain (Loss) [Line Items]

Derivative gains and (losses) in the Statements of Consolidated Income

(3)

$ 6

(58)

$ (38)

Increased (decreased) natural gas revenues from the unrealized net gains (losses) of derivative instruments

(2)

(13)

(19)

Increased (decreased) natural gas expense from the unrealized net (gains) losses of derivative instruments

(6)

(5)

(21)

Net unrealized gain (loss) from derivative instruments

$ 4

$ (8)

$ 2

$ (5)

Term of normal weather used as the basis for weather hedges (in years)

Losses recognized from weather hedges

$ 1

$ (2)

$ 6

$ 5

Total fair value of the derivative instruments that contain credit risk contingent features that are in a net liability position

107

The aggregate fair value of assets already posted as collateral

Credit Risk Contingent Features assets

Natural Gas Contracts [Member] | Current Assets [Member]

^[5]

^[1],[2]

^[3],[4]

Natural Gas Contracts [Member] | Other Assets [Member]

^[5]

^[1],[2]

^[3],[4]

^[5]

^[1],[2]

^[3],[4]

Natural Gas Contracts [Member] | Current Liabilities [Member]

^[5]

^[1],[2]

^[3],[4]

^[5]

^[1],[2]

^[3],[4]

Natural Gas Contracts [Member] | Other Liabilities [Member]

^[5]

^[1],[2]

143

^[3],[4]

^[5]

^[1],[2]

^[3],[4]

Indexed Debt Securities Derivative [Member] | Current Liabilities [Member]

^[5]

^[1],[2]

^[3],[4]

^[1],[2]

^[3],[4]

$ 255

^[1],[2]

$ 255

^[1],[2]

$ 232

^[3],[4]

[1]	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 593 Bcf or a net 110 Bcf long position. Of the net long position, basis swaps constitute 65 Bcf and volumes associated with price stabilization activities of the Natural Gas Distribution business segment comprise 14 Bcf.
[2]	The net of total non-trading derivative assets and liabilities is a less than $1 million asset as shown on CenterPoint Energy's Condensed Consolidated Balance Sheets, and is comprised of the natural gas contracts derivative assets and liabilities separately shown above offset by collateral netting of $41 million.
[3]	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 626 billion cubic feet (Bcf) or a net 72 Bcf long position. Of the net long position, basis swaps constitute 63 Bcf and volumes associated with price stabilization activities of the Natural Gas Distribution business segment comprise 26 Bcf.
[4]	The net of total non-trading derivative assets and liabilities is a $15 million liability as shown on CenterPoint Energy's Condensed Consolidated Balance Sheets, and is comprised of the natural gas contracts derivative assets and liabilities separately shown above offset by collateral netting of $84 million.
[5]	Natural gas contracts are subject to master netting arrangements and are presented on a net basis in the Condensed Consolidated Balance Sheets. This netting causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets.

Fair Value Measurements (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

Jun. 30, 2011

Jun. 30, 2010

Jun. 30, 2011

Jun. 30, 2010

Dec. 31, 2010

Assets

$ 418

$ 368

524

491

255

232

Cash collateral posted with counterparties

305

316

Fair value measurement using significant unobservable input (level 3) reconciliation [Roll Forward]

Beginning balance

$ 4

$ (6)

Amount of total gains for the period included in earnings

Total unrealized gains or losses:

Included in earnings

Included in regulatory assets

(1)

Total settlements, gross:

Included in earnings

(2)

^[1]

(2)

^[2]

Included in regulatory assets

^[1]

^[2]

Ending balance

$ 5

Carrying Amount [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Long-term debt

8,850

9,303

Fair Value [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Long-term debt

9,671

10,071

Fair Value, Inputs, Level 1 [Member]

Assets

418

368

477

422

Fair Value, Inputs, Level 2 [Member]

Assets

255

232

167

Fair Value, Inputs, Level 3 [Member]

350

399

Assets

Netting Adjustments [Member]

Assets

^[3]

^[4]

^[3]

^[4]

(12)

^[3]

(12)

^[3]

(11)

^[4]

(12)

^[3]

(12)

^[3]

(11)

^[4]

^[3]

^[4]

(53)

^[3]

(53)

^[3]

(95)

^[4]

Basic earnings per share calculation:

$ (53)

^[3]

$ (53)

^[3]

$ (95)

^[4]

[1]	During both the three months ended June 30, 2010 and 2011, CenterPoint Energy did not have Level 3 purchases or sales.
[2]	During both the six months ended June 30, 2010 and 2011, CenterPoint Energy did not have Level 3 purchases or sales.
[3]	Amounts represent the impact of legally enforceable master netting agreements that allow CenterPoint Energy to settle positive and negative positions and also include cash collateral of $41 million posted with the same counterparties.
[4]	Amounts represent the impact of legally enforceable master netting agreements that allow CenterPoint Energy to settle positive and negative positions and also include cash collateral of $84 million posted with the same counterparties.

Goodwill (Details) - USD ($) $ in Millions	Jun. 30, 2011	Dec. 31, 2010
Goodwill Schedule [Line Items]
Goodwill	$ 1,696	$ 1,696
Natural Gas Distribution [Member]
Goodwill Schedule [Line Items]
Goodwill	746	746
Interstate Pipelines [Member]
Goodwill Schedule [Line Items]
Goodwill	579	579
Competitive Natural Gas Sales and Services [Member]
Goodwill Schedule [Line Items]
Goodwill	335	335
Field Services [Member]
Goodwill Schedule [Line Items]
Goodwill	25	25
Other Operations [Member]
Goodwill Schedule [Line Items]
Goodwill	$ 11	$ 11

Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
Comprehensive Income (Details) - USD ($) $ in Millions	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Comprehensive Income [Abstract]
Net income	$ 119	$ 81	$ 267	$ 195
Other comprehensive income:
Adjustment related to pension and other postretirement plans (net of tax of $1, $1, $3 and $3)	3	2	5	5
Total	3	2	5	5
Comprehensive income	122	83	272	200
Adjustment related to pension and postretirement plans	(109)		(109)		$ (114)
Net deferred loss from cash flow hedges	(3)		(3)		(3)
Total accumulated other comprehensive loss	(112)		(112)		$ (117)
Tax effects on adjustment to pension and other postretirement plans	$ 1	$ 1	$ 3	$ 3

Capital Stock (Details) - $ / shares	Jun. 30, 2011	Dec. 31, 2010
Capital Stock (Details) [Abstract]
Capital stock shares authorized (in shares)	1,020,000,000
Common stock shares authorized (in shares)	1,000,000,000
Common stock shares par value (in dollars per share)	$ 0.01
Cumulative preferred stock shares authorized (in shares)	20,000,000
Cumulative preferred stock par value (in dollars per share)	$ 0.01
Total common stock issued (in shares)	425,834,305	424,746,343
Total common stock outstanding (in shares)	425,834,139	424,746,177
Treasury stock (in shares)	166	166

Short-Term Borrowings and Long-term Debt (Details) $ in Millions		6 Months Ended	12 Months Ended
	Jan. 31, 2011 USD ($)	Jun. 30, 2011 USD ($)	Dec. 31, 2010 USD ($)	Dec. 31, 2011 USD ($)
Debt Instrument [Line Items]
Total short term borrowings		$ 109	$ 53
Long-term Debt [Abstract]
Long term debt		8,510	9,001
Commercial Paper [Member]
Debt Instrument [Line Items]
Total short term borrowings		$ 70
Long-term Debt [Abstract]
Long term debt			183
Expiration date of the revolving credit facilities		June 29, 2012
Bank loans due 2012 [Member] \| CenterPoint Houston [Member]
Long-term Debt [Abstract]
Amount of outstanding letters of credit		$ 4	4
Total credit facility amount		$ 289	$ 289
Expiration date of the revolving credit facilities		June 29, 2012	June 29, 2012
Revolving credit facility borrowing rate		LIBOR+.0045	LIBOR+.0045
Percentage on limitation of debt to total capitalization under covenant (in hundredths)		65.00%
Utilization fee on borrowings exceeding fifty percent of total credit facility (in hundredths)		0.0005
Percentage of utilization of credit facility (in hundredths)		more than 0.5
Bank loans due 2012 [Member] \| CenterPoint Energy [Member]
Long-term Debt [Abstract]
Amount of outstanding letters of credit		$ 17	$ 20
Total credit facility amount		$ 1,200	$ 1,200
Expiration date of the revolving credit facilities		June 29, 2012	June 29, 2012
Revolving credit facility borrowing rate		LIBOR+.0055	LIBOR+.0055
Debt to EBITDA covenant ratio, before amendment		5	5
Debt to EBITDA covenant ratio, amendment		5.5	5.5
System restoration costs threshold for increase in permitted debt to EBITDA covenant ratio		$ 100	$ 100
Utilization fee on borrowings exceeding fifty percent of total credit facility (in hundredths)		0.0005
Percentage of utilization of credit facility (in hundredths)		more than 0.5
Bank loans due 2012 [Member] \| CERC Corp [Member]
Long-term Debt [Abstract]
Total credit facility amount		$ 915
Expiration date of the revolving credit facilities		June 29, 2012
Revolving credit facility borrowing rate		LIBOR+.0045
Percentage on limitation of debt to total capitalization under covenant (in hundredths)		65.00%
Utilization fee on borrowings exceeding fifty percent of total credit facility (in hundredths)		0.0005
Percentage of utilization of credit facility (in hundredths)		more than 0.5
Senior notes 2013 to 2037 [Member] \| CERC Corp [Member]
Long-term Debt [Abstract]
Extinguishment of debt, principal amount		$ 397
Debt Instrument, Interest Rate, Stated Percentage (in hundredths)		7.875%
CERC Corp. receivables facility [Member]
Debt Instrument [Line Items]
Receivables facility range, minimum		$ 160
Receivables facility range, maximum		375
Receivable facility maximum advance capacity		300	160
Product Financing Arrangement [Member]
Debt Instrument [Line Items]
Total short term borrowings		39	$ 53
Senior notes issued, due 2021 (CERC Corp. senior notes) [Member] \| CERC Corp [Member]
Long-term Debt [Abstract]
Amount of senior notes issued (CERC Corp. senior notes)	$ 250
Debt Instrument, Interest Rate, Stated Percentage (in hundredths)	4.50%
Senior notes issued, due 2011 (CERC Corp. senior notes) [Member] \| CenterPoint Energy [Member]
Long-term Debt [Abstract]
Amount of senior notes issued (CERC Corp. senior notes)				$ 550
Senior notes issued, due 2011 (CERC Corp. senior notes) [Member] \| CERC Corp [Member]
Long-term Debt [Abstract]
Extinguishment of debt, principal amount		$ 550
Debt Instrument, Interest Rate, Stated Percentage (in hundredths)		7.75%
Senior notes issued, due 2041 (CERC Corp. senior notes) [Member] \| CERC Corp [Member]
Long-term Debt [Abstract]
Amount of senior notes issued (CERC Corp. senior notes)	$ 300
Debt Instrument, Interest Rate, Stated Percentage (in hundredths)	5.85%
Senior notes issued, due 2021 (CERC exchange offer) [Member] \| CERC Corp [Member]
Long-term Debt [Abstract]
Amount of senior notes issued (CERC Corp. senior notes)	$ 343
Debt Instrument, Interest Rate, Stated Percentage (in hundredths)	4.50%
Amount of cash consideration provided related to CERC exchange offer	$ 114
Unamortized debt issuance cost	$ 58

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
Income Taxes (Details) - USD ($) $ in Millions	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Income Taxes [Abstract]
Effective tax rate (in hundredths)	37.00%	36.00%	37.00%	43.00%
Amount of non-cash recorded to income tax expense as result of change in tax law				$ 21
Amount of reduction to deferred tax assets due to actuarially determined net present value of lost future health care deductions		$ 32		32
Amount of adjustment to regulatory assets due to actuarially determined net present value of lost future health care deductions		11		11
Range of change possible in unrecognized tax benefits over the next 12 months, minimum	$ 284		$ 284
Range of change possible in unrecognized tax benefits over the next 12 months, maximum	$ (17)		$ (17)
Unrecognized tax benefits		314		314	$ 252
Portion of unrecognized tax benefits that, if recognized, would reduce the effective income tax rate		19		19	17
Interest accrued on unrecognized tax benefits		$ 16		$ 16	$ 12

Commitments and Contingencies (Details) $ in Thousands	6 Months Ended
Commitments and Contingencies (Details) $ in Thousands	Jun. 30, 2011 USD ($)
Legal Environmental And Other Regulatory Matters Legal Matters Gas Market Manipulation Cases Abstract
Recovery of compensatory damages sought by plaintiffs	in excess of 1 billion
Approximate number of gas market manipulation lawsuits naming CenterPoint and/or Reliant Energy (in number of lawsuits)	30
Number of gas market manipulation lawsuits pending for CenterPoint and its affiliates (in number of lawsuits)	2
Number of gas market mismeasurement lawsuits pending for CenterPoint and its affiliates (in number of lawsuits)	2
Approximate number of pipeline companies named in the mismeasurement lawsuits (in number of companies)	245
Number of gas measurement lawsuits seeking class certification and has four amendments (in number of cases)	1
Number of times gas measurement lawsuit was amended (in number of amendments)	4
Number of years the plaintiffs claim the defendants have engaged in the systematic mismeasurement of natural gas (in years)	25
Number of CenterPoint subsidiaries dismissed from the claims of the plaintiff (in number of claims)	2
Number of sites where remediation is complete, other than ongoing operations (in number of sites)	2
Number of remaining sites in the Minnesota service territory (in number of sites)	5
Number of the remaining sites in the Minnesota service territory where the company believes it has no liability (in number of sites)	2
Amount accrued for remediation of Minnesota sites (in number of sites)	$ 13,000
Minimum estimated remediation costs for the Minnesota sites	4,000
Maximum estimated remediation costs for the Minnesota sites	$ 35,000
Minimum years of remediation for the Minnesota sites (in years)	30
Maximum years of remediation for the Minnesota sites (in years)	50
Annual amount included in rates to fund normal on-going remediation costs	$ 285
Amount collected from insurance companies to be used for future environmental remediation	5,300
Approximate amount of undiscounted maximum potential demand charges under the transportation contracts	105,000
Approximate amount of collateral posted as security on transportation contracts	$ 7,000
Magnolia Gathering System [Member]
Schedule of Capital Expansion Projects
Expanded natural gas capacity per day (in million cubic feet)	700
Amount spent on original project scope for expansion	$ 320,000
Years lapsed under volume commitment (in number of years)	2
Years of volume commitment (in number of years)	10
Additional natural gas capacity per day under the expansion election (in million cubic feet)	200
Total capacity per day of system after expansion (in million cubic feet)	900
Total costs of additional expansion	$ 52,000
Potential additional natural gas capacity per day under potential additional expansion election (in million cubic feet)	800
Total capacity per day of system after potential additional expansion (in billion cubic feet)	1.7
Total estimatted costs of potential additional expansion	$ 240,000
Olympia Gathering System [Member]
Schedule of Capital Expansion Projects
Expanded natural gas capacity per day (in million cubic feet)	600
Amount spent on original project scope for expansion	$ 375,000
Years lapsed under volume commitment (in number of years)	2
Years of volume commitment (in number of years)	10
Potential additional natural gas capacity per day under potential additional expansion election (in million cubic feet)	520
Total capacity per day of system after potential additional expansion (in billion cubic feet)	1.1
Total estimatted costs of potential additional expansion	$ 200,000
Estimated remaining costs to complete expansion	50,000
Natural Gas supply commitments [Member]
Recorded Unconditional Purchase Obligation
2011	193,000
2012	439,000
2013	437,000
2014	314,000
2015	198,000
After 2015	$ 412,000

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

3 Months Ended

6 Months Ended

Jun. 30, 2011

Jun. 30, 2010

Jun. 30, 2011

Jun. 30, 2010

Net income

$ 119

$ 81

$ 267

$ 195

Weighted average shares outstanding (in shares)

425,638,000

399,515,000

425,330,000

396,203,000

Basic earnings per share (dollars per share)

$ 0.28

$ 0.20

$ 0.63

$ 0.49

Diluted earnings per share (dollars per share)

$ 0.28

$ 0.20

$ 0.62

$ 0.49

Net income

$ 119

$ 81

$ 267

$ 195

Weighted average shares outstanding (in shares)

425,638,000

399,515,000

425,330,000

396,203,000

Plus: Incremental shares from assumed conversions:

Stock options (in shares)

^[1]

401,000

560,000

379,000

568,000

Restricted stock (in shares)

2,245,000

1,918,000

2,245,000

1,918,000

Weighted average shares assuming dilution (in shares)

428,284,000

401,993,000

427,954,000

398,689,000

Diluted earnings per share:

Outstanding shares with the options to purchase not included in the computation of diluted earnings per share (in shares)

37,497

1,616,951

37,497

1,616,951

[1]

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

3 Months Ended

6 Months Ended

Jun. 30, 2011

Jun. 30, 2010

Jun. 30, 2011

Jun. 30, 2010

Dec. 31, 2010

$ 1,837

$ 1,756

$ 4,424

$ 4,779

303

263

667

620

Electric Transmission and Distribution [Member]

19,677

$ 20,111

^[1]

606

562

1,095

1,044

185

158

286

265

Sales to subsidiaries of NRG Retail LLC

9,873

9,817

133

132

259

267

Sales to subsidiaries of TXU Energy Retail Company LLC

Natural Gas Distribution [Member]

448

462

1,655

1,995

155

149

Competitive Natural Gas Sales and Services [Member]

4,438

4,575

581

550

1,278

1,394

(6)

Interstate Pipelines [Member]

1,110

1,190

111

113

224

216

136

139

3,766

3,672

Field Services [Member]

166

124

Other Operations [Member]

1,832

1,803

Pension and other postemployment related regulatory assets included in total assets of Other Operations

^[2]

2,136

2,184

680

704

Reconciling Eliminations [Member]

(50)

(62)

(110)

(119)

$ 0

Indexed Debt Securities Derivative [Member] | Gains (losses) in Other Income (Expense) [Member]

$ (3,478)

$ (3,130)

[1]

[2]

Included in total assets of Other Operations as of December 31, 2010 and June 30, 2011 are pension and other postemployment related regulatory assets of $704 million and $680 million, respectively.

Subsequent Events (Details) - Dividend Declared [Member]	6 Months Ended
	Jun. 30, 2011 USD ($)
Subsequent Event [Line Items]
Subsequent Event, Date	Jul. 19, 2011
Subsequent Event, Amount	$ 0.1975

Label

Element

Value

Derivative gains and (losses) in the Statements of Consolidated Income

cnp_DerivativeGainsAndLossesInStatementsOfConsolidatedIncome

$ 32,000,000

Derivative gains and (losses) in the Statements of Consolidated Income

cnp_DerivativeGainsAndLossesInStatementsOfConsolidatedIncome

Derivative gains and (losses) in the Statements of Consolidated Income

cnp_DerivativeGainsAndLossesInStatementsOfConsolidatedIncome

5,000,000

Derivative gains and (losses) in the Statements of Consolidated Income

cnp_DerivativeGainsAndLossesInStatementsOfConsolidatedIncome

(23,000,000)

Natural Gas Contracts [Member] | Gains (Losses) in Revenue [Member]

Derivative gains and (losses) in the Statements of Consolidated Income

cnp_DerivativeGainsAndLossesInStatementsOfConsolidatedIncome

5,000,000

Derivative gains and (losses) in the Statements of Consolidated Income

cnp_DerivativeGainsAndLossesInStatementsOfConsolidatedIncome

9,000,000

Derivative gains and (losses) in the Statements of Consolidated Income

cnp_DerivativeGainsAndLossesInStatementsOfConsolidatedIncome

49,000,000

Derivative gains and (losses) in the Statements of Consolidated Income

cnp_DerivativeGainsAndLossesInStatementsOfConsolidatedIncome

14,000,000

Natural Gas Contracts [Member] | Gains (Losses) in Expense: Natural Gas [Member]

cnp_DerivativeInstrumentsPriceStabilizationCost

(25,000,000)

cnp_DerivativeInstrumentsPriceStabilizationCost

(17,000,000)

cnp_DerivativeInstrumentsPriceStabilizationCost

(50,000,000)