Consolidated Statement of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net Income	$ 1,141	$ 1,062	$ 1,003
OTHER COMPREHENSIVE INCOME/(LOSS), NET OF TAXES
Pension plan liability adjustments, net	5	(18)	2
TOTAL OTHER COMPREHENSIVE INCOME/(LOSS), NET OF TAXES	5	(18)	2
COMPREHENSIVE INCOME	1,146	1,044	1,005
Preferred stock dividend requirements of subsidiary	(3)	(11)	(11)
COMPREHENSIVE INCOME FOR COMMON STOCK	1,143	1,033	994
CECONY [Member]
Net Income	1,017	989	904
OTHER COMPREHENSIVE INCOME/(LOSS), NET OF TAXES
Pension plan liability adjustments, net	(1)	(2)	(2)
TOTAL OTHER COMPREHENSIVE INCOME/(LOSS), NET OF TAXES	(1)	(2)	(2)
COMPREHENSIVE INCOME	1,016	987	902
Preferred stock dividend requirements of subsidiary	$ (3)	$ (11)	$ (11)