v2.4.0.8
Document and Entity Supplemental Information Document (USD $)
6 Months Ended
Jun. 30, 2015
Jul. 31, 2015
Jun. 30, 2014
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, 2015    
Document Fiscal Year Focus 2015    
Document Fiscal Period Focus Q2    
Amendment Flag false    
Entity Common Stock, Shares Outstanding   430,261,710  
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Public Float     $ 10,907,234,073