v2.4.0.6
Document and Entity Supplemental Information Document (USD $)
6 Months Ended
Jun. 30, 2013
Jul. 18, 2013
Jun. 30, 2012
Entity Information [Line Items]      
Entity Registrant Name CENTERPOINT ENERGY INC.    
Entity Central Index Key 0001130310    
Current Fiscal Year End Date --12-31    
Entity Filer Category Large Accelerated Filer    
Document Type 10-Q    
Document Period End Date Jun. 30, 2013    
Document Fiscal Year Focus 2013    
Document Fiscal Period Focus Q2    
Amendment Flag false    
Entity Common Stock, Shares Outstanding   428,621,467  
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Public Float     $ 8,760,880,387