Capitalization - Common Stock (Details) - USD ($) $ in Millions	1 Months Ended
	Mar. 31, 2025	Dec. 31, 2024	Dec. 31, 2025	Dec. 31, 2023
Schedule of Capitalization [Line Items]
Common stock, shares authorized (in shares)		500,000,000	500,000,000
Common stock, shares outstanding (in shares)		346,597,693	361,121,447
Treasury shares (in shares)		33,753,963	33,753,963
Stock repurchases (in shares)				10,543,263
Issuance of common shares - public offering (in shares)	6,300,000	7,000,000
Proceeds from issuance of common stock	$ 631	$ 677
CECONY
Schedule of Capitalization [Line Items]
Common stock, shares authorized (in shares)		340,000,000	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