Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 22, 2021	Jun. 30, 2020
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Entity File Number	1-31447
Entity Registrant Name	CenterPoint Energy, Inc.
Entity Tax Identification Number	74-0694415
Entity Incorporation, State or Country Code	TX
Entity Address, Address Line One	1111 Louisiana
Entity Address, City or Town	Houston,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77002
City Area Code	(713)
Local Phone Number	207-1111
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 10,142,624,694
Entity Common Stock, Shares Outstanding		551,579,922
Entity Central Index Key	0001130310
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Common Stock, $0.01 par value | New York Stock Exchange
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	CNP
Security Exchange Name	NYSE
Common Stock, $0.01 par value | Chicago Stock Exchange
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	CNP
Security Exchange Name	CHX
Depositary shares, each representing a 1/20th interest in a share of 7.00% Series B Mandatory Convertible Preferred Stock, $0.01 par value | New York Stock Exchange
Entity Information [Line Items]
Title of 12(b) Security	Depositary shares, each representing a 1/20th interest in a share of 7.00% Series B Mandatory Convertible Preferred Stock, $0.01 par value
Trading Symbol	CNP/PB
Security Exchange Name	NYSE
CenterPoint Energy Houston Electric, LLC
Entity Information [Line Items]
Entity File Number	1-3187
Entity Registrant Name	CenterPoint Energy Houston Electric, LLC
Entity Tax Identification Number	22-3865106
Entity Incorporation, State or Country Code	TX
Entity Address, Address Line One	1111 Louisiana
Entity Address, City or Town	Houston,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77002
City Area Code	(713)
Local Phone Number	207-1111
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			0
Entity Common Stock, Shares Outstanding		1,000
Entity Central Index Key	0000048732
CenterPoint Energy Houston Electric, LLC | 9.15% First Mortgage Bonds due 2021 | New York Stock Exchange
Entity Information [Line Items]
Title of 12(b) Security	9.15% First Mortgage Bonds due 2021
Trading Symbol	n/a
Security Exchange Name	NYSE
CenterPoint Energy Houston Electric, LLC | 6.95% General Mortgage Bonds due 2033 | New York Stock Exchange
Entity Information [Line Items]
Title of 12(b) Security	6.95% General Mortgage Bonds due 2033
Trading Symbol	n/a
Security Exchange Name	NYSE
CenterPoint Energy Resources Corp.
Entity Information [Line Items]
Entity File Number	1-13265
Entity Registrant Name	CenterPoint Energy Resources Corp.
Entity Tax Identification Number	76-0511406
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	1111 Louisiana
Entity Address, City or Town	Houston,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77002
City Area Code	(713)
Local Phone Number	207-1111
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 0
Entity Common Stock, Shares Outstanding		1,000
Entity Central Index Key	0001042773
CenterPoint Energy Resources Corp. | 6.625% Senior Notes due 2037 | New York Stock Exchange
Entity Information [Line Items]
Title of 12(b) Security	6.625% Senior Notes due 2037
Trading Symbol	n/a
Security Exchange Name	NYSE