Capitalization - Common Stock (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) dealer $ / shares shares	Dec. 31, 2022 USD ($) shares	Dec. 31, 2021 USD ($)
Schedule of Capitalization [Line Items]
Common stock, shares authorized (in shares)	500,000,000
Common stock, shares outstanding (in shares)	345,415,772	354,962,058
Treasury shares (in shares)	33,753,963	23,210,700
Number of dealers | dealer	2
Stock repurchase program, authorized amount | $	$ 1
Preferred stock, par or stated value per share (in usd per share) | $ / shares	$ 0.10
Repurchase of common shares | $	$ 1,000	$ 0	$ 0
Treasury stock, shares, acquired	10,543,263
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