Subsequent Events	12 Months Ended
Dec. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Completion of Sale of Arkansas and Oklahoma Natural Gas businesses (CenterPoint Energy and CERC) On January 10, 2022, CERC Corp. completed the sale of its Arkansas and Oklahoma Natural Gas businesses. For additional information, see Note 4. CERC Dividend On February 11, 2022, CERC paid a dividend of $720 million to its parent, Utility Holding.

The entire disclosure for significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, catastrophic loss, significant foreign exchange rate changes, loans to insiders or affiliates, and transactions not in the ordinary course of business.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-URI http://asc.fasb.org/topic&trid=2122774

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662

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