Consolidated Statement of Capitalization - USD ($) shares in Millions, $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Schedule of Capitalization, Equity [Line Items]
TOTAL EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS (in shares)	305	293
TOTAL EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS	$ 14,325	$ 13,086
Pension plan liability adjustments, net of taxes	(24)	(31)
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	(3)	(3)
TOTAL ACCUMULATED OTHER COMPREHENSIVE LOSS, NET OF TAXES	(27)	(34)
Equity	14,298	13,052
Noncontrolling interest	8	9
TOTAL EQUITY (See Statement of Equity)	$ 14,306	$ 13,061
CECONY
Schedule of Capitalization, Equity [Line Items]
TOTAL EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS (in shares)	235	235
TOTAL EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS	$ 11,836	$ 11,424
Pension plan liability adjustments, net of taxes	(4)	(6)
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	(3)	(3)
TOTAL ACCUMULATED OTHER COMPREHENSIVE LOSS, NET OF TAXES	(7)	(9)
Equity	11,829	11,415
TOTAL SHAREHOLDER’S EQUITY (See Statement of Shareholder’s Equity)	$ 11,829	$ 11,415