Divestitures (CenterPoint Energy and CERC) - Discontinued Operations (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	Dec. 02, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Common and preferred units acquired (as a percent)						100.00%
Equity in earnings of unconsolidated affiliate, net			$ 0	$ 175
Income tax expense	$ 0	$ 16	0	41
Net income from discontinued operations	0	51	0	134
Distributions from unconsolidated affiliate - operating			0	77
Current assets	0		0		$ 2,338
Current liabilities	0		0		562
Operating revenues	1,944	1,742	4,707	4,289
Depreciation and amortization	327	327	645	634
Operating income	351	296	828	749
Net income attributable to Enable Common Units	179	221	697	555
CERC
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Current assets	0		0		2,084
Current liabilities	0		0		$ 562
Operating revenues	796	721	2,560	2,316
Depreciation and amortization	113	118	220	236
Operating income	$ 69	88	$ 379	396
Discontinued Operations | Enable Midstream Partners
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Equity in earnings of unconsolidated affiliate, net		67		175
Income from discontinued operations before income taxes		67		175
Income tax expense		16		41
Net income from discontinued operations		51		134
Distributions from unconsolidated affiliate - operating				77
Cash Distribution		47		95
Natural gas expenses, includes transportation and storage costs		16		48
Current assets						$ 594
Non-current assets						11,227
Current liabilities						1,254
Non-current liabilities						3,281
Non-controlling interest						26
Preferred equity						362
Accumulated other comprehensive loss						(1)
Enable partners’ equity						6,899
CenterPoint Energy’s ownership interest in Enable partners’ equity						3,701
CenterPoint Energy’s basis difference						(2,732)
CenterPoint Energy’s equity method investment in Enable						$ 969
Operating revenues		787		1,757
Cost of sales, excluding depreciation and amortization		426		945
Depreciation and amortization		103		209
Operating income		124		330
Net income attributable to Enable Common Units		79		234
CenterPoint Energy’s interest		42		125
Basis difference amortization		25		50
Discontinued Operations | Enable Midstream Partners | CERC
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Natural gas expenses, includes transportation and storage costs		$ 16		$ 48
Discontinued Operations | Enable Midstream Partners | Enable Common Units
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Distribution received (in dollars per unit)		$ 0.16525		$ 0.33050
Cash Distribution		$ 38		$ 77
Discontinued Operations | Enable Midstream Partners | Enable Series A Preferred Units
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Distribution received (in dollars per unit)		$ 0.58730		$ 1.21230
Cash Distribution		$ 9		$ 18