Consolidated Statement of Capitalization - USD ($) shares in Millions, $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Schedule of Capitalization, Equity [Line Items]
TOTAL EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS	$ 13,086	$ 12,621
TOTAL EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS (Shares)	293	293
Pension plan liability adjustments, net of taxes	$ (31)	$ (42)
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	(34)	(45)
Equity	13,052	12,576
Noncontrolling interest	9	9
TOTAL EQUITY (See Statement of Equity)	13,061	12,585
CECONY
Schedule of Capitalization, Equity [Line Items]
TOTAL EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS	$ 11,424	$ 11,199
TOTAL EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS (Shares)	235	235
Pension plan liability adjustments, net of taxes	$ (6)	$ (8)
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	(9)	(11)
Equity	11,415	11,188
TOTAL COMMON SHAREHOLDER’S EQUITY (See Statement of Shareholder’s Equity)	$ 11,415	$ 11,188