Income Tax - Summary of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	$ 17	$ 14	$ 13
Additions based on tax positions related to the current year	3	3	0
Additions based on tax positions of prior years	6	2	1
Reductions for tax positions of prior years	(1)	(2)	0
Settlements	(2)	0	0
Balance at end of period	23	17	14
CECONY
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	5	3	2
Additions based on tax positions related to the current year	2	2	0
Additions based on tax positions of prior years	1	1	1
Reductions for tax positions of prior years	0	(1)	0
Settlements	0	0	0
Balance at end of period	$ 8	$ 5	$ 3