Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended		6 Months Ended
	May 01, 2026	Apr. 29, 2026	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Basic and diluted earnings (loss) per share attributable to Clearway Energy, Inc. common stockholders
Net income (loss) attributable to Clearway Energy, Inc.			$ 122	$ 30	$ (41)	$ 27
As Previously Reported
Basic and diluted earnings (loss) per share attributable to Clearway Energy, Inc. common stockholders
Net income (loss) attributable to Clearway Energy, Inc.				33		37
Adjustments
Basic and diluted earnings (loss) per share attributable to Clearway Energy, Inc. common stockholders
Net income (loss) attributable to Clearway Energy, Inc.				(3)		(10)
Common Class A
Basic and diluted earnings (loss) per share attributable to Clearway Energy, Inc. common stockholders
Net income (loss) attributable to Clearway Energy, Inc.				$ 9		$ 8
Weighted average number shares outstanding - basic (in shares)			11,000,000	35,000,000	23,000,000	35,000,000
Weighted average number of shares outstanding - diluted (in shares)			11,000,000	35,000,000	23,000,000	35,000,000
Earnings (loss) per weighted average common share — basic (in dollars per share)			$ 1.00	$ 0.25	$ (0.34)	$ 0.23
Earnings (loss) per weighted average common share — diluted (in dollars per share)			$ 1.00	$ 0.25	$ (0.34)	$ 0.23
Common Class A | Clearway Energy, Inc.
Basic and diluted earnings (loss) per share attributable to Clearway Energy, Inc. common stockholders
Net income (loss) attributable to Clearway Energy, Inc.			$ 11		$ (8)
Weighted average number shares outstanding - basic (in shares)			11,000,000		23,000,000
Weighted average number of shares outstanding - diluted (in shares)			11,000,000		23,000,000
Earnings (loss) per weighted average common share — basic (in dollars per share)			$ 1.00		$ (0.34)
Earnings (loss) per weighted average common share — diluted (in dollars per share)			$ 1.00		$ (0.34)
Common Class A | As Previously Reported
Basic and diluted earnings (loss) per share attributable to Clearway Energy, Inc. common stockholders
Net income (loss) attributable to Clearway Energy, Inc.				$ 10		$ 11
Weighted average number shares outstanding - basic (in shares)				35,000,000		35,000,000
Weighted average number of shares outstanding - diluted (in shares)				35,000,000		35,000,000
Earnings (loss) per weighted average common share — basic (in dollars per share)				$ 0.28		$ 0.31
Earnings (loss) per weighted average common share — diluted (in dollars per share)				$ 0.28		$ 0.31
Common Class A | Adjustments
Basic and diluted earnings (loss) per share attributable to Clearway Energy, Inc. common stockholders
Net income (loss) attributable to Clearway Energy, Inc.				$ (1)		$ (3)
Weighted average number shares outstanding - basic (in shares)				0		0
Weighted average number of shares outstanding - diluted (in shares)				0		0
Earnings (loss) per weighted average common share — basic (in dollars per share)				$ (0.03)		$ (0.08)
Earnings (loss) per weighted average common share — diluted (in dollars per share)				$ (0.03)		$ (0.08)
Common Class C
Basic and diluted earnings (loss) per share attributable to Clearway Energy, Inc. common stockholders
Net income (loss) attributable to Clearway Energy, Inc.				$ 21		$ 19
Weighted average number shares outstanding - basic (in shares)			110,000,000	83,000,000	98,000,000	83,000,000
Weighted average number of shares outstanding - diluted (in shares)			110,000,000	83,000,000	98,000,000	83,000,000
Earnings (loss) per weighted average common share — basic (in dollars per share)			$ 1.00	$ 0.25	$ (0.34)	$ 0.23
Earnings (loss) per weighted average common share — diluted (in dollars per share)			$ 1.00	$ 0.25	$ (0.34)	$ 0.23
Shares converted (in shares)	1	1
Common Class C | Clearway Energy, Inc.
Basic and diluted earnings (loss) per share attributable to Clearway Energy, Inc. common stockholders
Net income (loss) attributable to Clearway Energy, Inc.			$ 111		$ (33)
Weighted average number shares outstanding - basic (in shares)			110,000,000		98,000,000
Weighted average number of shares outstanding - diluted (in shares)			110,000,000		98,000,000
Earnings (loss) per weighted average common share — basic (in dollars per share)			$ 1.00		$ (0.34)
Earnings (loss) per weighted average common share — diluted (in dollars per share)			$ 1.00		$ (0.34)
Common Class C | As Previously Reported
Basic and diluted earnings (loss) per share attributable to Clearway Energy, Inc. common stockholders
Net income (loss) attributable to Clearway Energy, Inc.				$ 23		$ 26
Weighted average number shares outstanding - basic (in shares)				83,000,000		83,000,000
Weighted average number of shares outstanding - diluted (in shares)				83,000,000		83,000,000
Earnings (loss) per weighted average common share — basic (in dollars per share)				$ 0.28		$ 0.31
Earnings (loss) per weighted average common share — diluted (in dollars per share)				$ 0.28		$ 0.31
Common Class C | Adjustments
Basic and diluted earnings (loss) per share attributable to Clearway Energy, Inc. common stockholders
Net income (loss) attributable to Clearway Energy, Inc.				$ (2)		$ (7)
Weighted average number shares outstanding - basic (in shares)				0		0
Weighted average number of shares outstanding - diluted (in shares)				0		0
Earnings (loss) per weighted average common share — basic (in dollars per share)				$ (0.03)		$ (0.08)
Earnings (loss) per weighted average common share — diluted (in dollars per share)				$ (0.03)		$ (0.08)