Consolidated Statement Of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
NET INCOME	$ 1,062	$ 1,003	$ 879
OTHER COMPREHENSIVE INCOME/(LOSS), NET OF TAXES
Pension plan liability adjustments, net of taxes	(18)	2	26
Less: Reclassification adjustment for (gains)/losses included in net income, net of $1 taxes in 2009			1
TOTAL OTHER COMPREHENSIVE INCOME/(LOSS), NET OF TAXES	(18)	2	25
COMPREHENSIVE INCOME	1,044	1,005	904
Preferred stock dividend requirements of subsidiary	(11)	(11)	(11)
COMPREHENSIVE INCOME FOR COMMON STOCK	1,033	994	893
CECONY [Member]
NET INCOME	989	904	792
OTHER COMPREHENSIVE INCOME/(LOSS), NET OF TAXES
Pension plan liability adjustments, net of taxes	(2)	(2)	16
TOTAL OTHER COMPREHENSIVE INCOME/(LOSS), NET OF TAXES	(2)	(2)	16
COMPREHENSIVE INCOME	987	902	808
Preferred stock dividend requirements of subsidiary	$ (11)	$ (11)	$ (11)