Capitalization - Common Stock (Details) - USD ($) $ in Millions	1 Months Ended
	Jun. 30, 2021	Dec. 31, 2021	Dec. 31, 2020
Schedule of Capitalization [Line Items]
Common stock, shares authorized (in shares)		500,000,000
Common stock, shares outstanding (in shares)		353,983,712	342,297,534
Treasury shares (in shares)		23,210,700	23,210,700
Shares issued (in shares)	10,100,000
Proceeds from issuance of equity	$ 775
CECONY
Schedule of Capitalization [Line Items]
Common stock, shares authorized (in shares)		340,000,000
Common stock, shares outstanding (in shares)		235,488,094	235,488,094
Treasury shares (in shares)		21,976,200	21,976,200