Divestitures (CenterPoint Energy and CERC) (Policies)	3 Months Ended
Mar. 31, 2021
Discontinued Operations and Disposal Groups [Abstract]
Consolidation	The Infrastructure Services Disposal Group provided pipeline construction and repair services to CenterPoint Energy’s and CERC’s Natural Gas. In accordance with consolidation guidance in ASC 980—Regulated Operations, costs incurred by Natural Gas utilities for these pipeline construction and repair services are not eliminated in consolidation when capitalized and included in rate base by the Natural Gas utility. Amounts charged for these services that are not capitalized are included primarily in Operation and maintenance expenses.

Disclosure of accounting policy regarding (1) the principles it follows in consolidating or combining the separate financial statements, including the principles followed in determining the inclusion or exclusion of subsidiaries or other entities in the consolidated or combined financial statements and (2) its treatment of interests (for example, common stock, a partnership interest or other means of exerting influence) in other entities, for example consolidation or use of the equity or cost methods of accounting. The accounting policy may also address the accounting treatment for intercompany accounts and transactions, noncontrolling interest, and the income statement treatment in consolidation for issuances of stock by a subsidiary.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84158767&loc=d3e18780-107790

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=109239629&loc=d3e5614-111684

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