Consolidated Statement of Capitalization - USD ($) shares in Millions, $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Schedule of Capitalization, Equity [Line Items]
TOTAL EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS (in shares)	342	333
TOTAL EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	$ 18,872	$ 18,041
Pension plan liability adjustments, net of taxes	(23)	(17)
Unrealized gains/(losses) on derivatives qualified as cash flow hedges, less reclassification adjustment for gains/(losses) included in net income and reclassification adjustment for unrealized losses included in regulatory assets, net of taxes	(2)	(2)
TOTAL ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAXES	(25)	(19)
Equity	18,847	18,022
Noncontrolling interest	218	191
TOTAL EQUITY (See Statement of Equity)	$ 19,065	$ 18,213
CECONY
Schedule of Capitalization, Equity [Line Items]
TOTAL EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS (in shares)	235	235
TOTAL EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	$ 14,856	$ 14,153
Pension plan liability adjustments, net of taxes	(5)	0
Unrealized gains/(losses) on derivatives qualified as cash flow hedges, less reclassification adjustment for gains/(losses) included in net income and reclassification adjustment for unrealized losses included in regulatory assets, net of taxes	(2)	(6)
TOTAL ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAXES	(7)	(6)
Equity	14,849	14,147
TOTAL SHAREHOLDER’S EQUITY (See Statement of Shareholder’s Equity)	$ 14,849	$ 14,147