Schedule of Capitalization - Equity (USD $) In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Schedule of Capitalization, Equity [Line Items]
TOTAL COMMON SHAREHOLDERS' EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS	$ 12,621	$ 12,270
TOTAL COMMON SHAREHOLDERS' EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS (in shares)	292,876,196	292,872,396
Pension plan liability adjustments, net of taxes	(42)	(22)
Unrealized gains/(losses) on derivatives qualified as cash flow hedges, less reclassification adjustment for gains/(losses) included in net income and reclassification adjustment	(3)	(3)
TOTAL ACCUMULATED OTHER COMPREHENSIVE LOSS, NET OF TAXES	(45)	(25)
Common Shareholders' Equity	12,576	12,245
Noncontrolling interest	9
TOTAL EQUITY (See Statement of Equity)	12,585	12,245
CECONY [Member]
Schedule of Capitalization, Equity [Line Items]
TOTAL COMMON SHAREHOLDERS' EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS	11,199	10,853
TOTAL COMMON SHAREHOLDERS' EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS (in shares)	235,488,094	235,488,094
Pension plan liability adjustments, net of taxes	(8)	(3)
Unrealized gains/(losses) on derivatives qualified as cash flow hedges, less reclassification adjustment for gains/(losses) included in net income and reclassification adjustment	(3)	(3)
TOTAL ACCUMULATED OTHER COMPREHENSIVE LOSS, NET OF TAXES	(11)	(6)
Common Shareholders' Equity	11,188	10,847
TOTAL COMMON SHAREHOLDER'S EQUITY (See Statement of Shareholder's Equity)	$ 11,188	$ 10,847