Segment Reporting (Details) - USD ($) $ in Millions		3 Months Ended			6 Months Ended	9 Months Ended	12 Months Ended
	May 31, 2023	Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2025	Sep. 30, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting
Operating revenues							$ 1,429	$ 1,371	$ 1,314
Cost of operations, exclusive of depreciation, amortization and accretion shown separately below							530	501	473
Depreciation, amortization and accretion							682	627	526
Impairment losses							0	0	12
General and administrative							41	39	36
Transaction and integration costs							16	8	4
Operating income (loss)							160	196	263
Equity in earnings of unconsolidated affiliates							31	35	12
Other income, net							29	48	52
Loss on debt extinguishment							(8)	(5)	(6)
Interest expense							(387)	(307)	(337)
Income (loss) before income taxes							(175)	(33)	(16)
Income tax expense (benefit)							56	30	(2)
Net income (loss)	$ 8						(231)	(63)	(14)
Less: Net loss attributable to noncontrolling interests and redeemable noncontrolling interests		$ (172)	$ (18)	$ (101)	$ (119)	$ (291)	(400)	(151)	(93)
Net Income (Loss) Attributable to Clearway Energy, Inc.		$ 232	$ 30	$ (3)	$ 27	$ 259	169	88	79
Equity investments in affiliates							291	309
Capital expenditures							196	188
Total Assets							16,655	14,329
Operating Segments
Segment Reporting
Operating revenues							1,429	1,371	1,314
Operating Segments | Flexible Generation
Segment Reporting
Operating revenues							291	342	420
Cost of operations, exclusive of depreciation, amortization and accretion shown separately below							109	137	154
Depreciation, amortization and accretion							112	115	129
Impairment losses									0
General and administrative							0	0	0
Transaction and integration costs							0	0	0
Operating income (loss)							70	90	137
Equity in earnings of unconsolidated affiliates							1	3	3
Other income, net							4	6	4
Loss on debt extinguishment							0	0	0
Interest expense							(35)	(35)	(35)
Income (loss) before income taxes							40	64	109
Income tax expense (benefit)							0	0	0
Net income (loss)							40	64	109
Less: Net loss attributable to noncontrolling interests and redeemable noncontrolling interests							0	0	0
Net Income (Loss) Attributable to Clearway Energy, Inc.							40	64	109
Equity investments in affiliates							72	75
Capital expenditures							9	9
Total Assets							1,803	1,933
Operating Segments | Renewables & Storage
Segment Reporting
Operating revenues							1,138	1,029	894
Cost of operations, exclusive of depreciation, amortization and accretion shown separately below							421	367	321
Depreciation, amortization and accretion							570	512	397
Impairment losses									12
General and administrative							0	0	0
Transaction and integration costs							0	0	0
Operating income (loss)							147	150	164
Equity in earnings of unconsolidated affiliates							30	32	9
Other income, net							22	31	24
Loss on debt extinguishment							(8)	(5)	(6)
Interest expense							(252)	(176)	(205)
Income (loss) before income taxes							(61)	32	(14)
Income tax expense (benefit)							(1)	1	(2)
Net income (loss)							(60)	31	(12)
Less: Net loss attributable to noncontrolling interests and redeemable noncontrolling interests							(560)	(236)	(162)
Net Income (Loss) Attributable to Clearway Energy, Inc.							500	267	150
Equity investments in affiliates							219	234
Capital expenditures							187	179
Total Assets							14,557	12,236
Corporate
Segment Reporting
Operating revenues							0	0	0
Cost of operations, exclusive of depreciation, amortization and accretion shown separately below							0	(3)	(2)
Depreciation, amortization and accretion							0	0	0
Impairment losses									0
General and administrative							41	39	36
Transaction and integration costs							16	8	4
Operating income (loss)							(57)	(44)	(38)
Equity in earnings of unconsolidated affiliates							0	0	0
Other income, net							3	11	24
Loss on debt extinguishment							0	0	0
Interest expense							(100)	(96)	(97)
Income (loss) before income taxes							(154)	(129)	(111)
Income tax expense (benefit)							57	29	0
Net income (loss)							(211)	(158)	(111)
Less: Net loss attributable to noncontrolling interests and redeemable noncontrolling interests							160	85	69
Net Income (Loss) Attributable to Clearway Energy, Inc.							(371)	(243)	$ (180)
Equity investments in affiliates							0	0
Capital expenditures							0	0
Total Assets							$ 295	$ 160
Southern California Edison | Flexible Generation
Segment Reporting
Customers percentage of total revenue							7.00%	7.00%	11.00%
Southern California Edison | Renewables & Storage
Segment Reporting
Customers percentage of total revenue							15.00%	17.00%	13.00%
PG&E | Flexible Generation
Segment Reporting
Customers percentage of total revenue							2.00%	3.00%	4.00%
PG&E | Renewables & Storage
Segment Reporting
Customers percentage of total revenue							14.00%	14.00%	13.00%
CALIFORNIA | Revenue Benchmark | Geographic Concentration Risk
Segment Reporting
Percentage of total operating revenue and assets							58.00%
CALIFORNIA | Assets, Total | Geographic Concentration Risk
Segment Reporting
Percentage of total operating revenue and assets							45.00%