Consolidated Statement of Common Shareholders' Equity (USD $) In Millions, except Share data	Total	CECONY [Member]	Common Stock [Member]	Common Stock [Member] CECONY [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member] CECONY [Member]	Retained Earnings [Member]	Retained Earnings [Member] CECONY [Member]	Treasury Stock [Member]	Capital Stock Expense [Member]	Capital Stock Expense [Member] CECONY [Member]	Accumulated Other Comprehensive Income/(Loss) [Member]	Accumulated Other Comprehensive Income/(Loss) [Member] CECONY [Member]	Repurchased Con Edison Stock [Member] CECONY [Member]
BALANCE at Dec. 31, 2010	$ 11,061	$ 9,923	$ 31	$ 589	$ 4,915	$ 4,234	$ 7,220	$ 6,132	$ (1,001)	$ (64)	$ (64)	$ (40)	$ (6)	$ (962)
BALANCE (In Shares) at Dec. 31, 2010			291,616,334	235,488,094					23,210,700
Net income for common stock	1,051	978					1,051
NET INCOME	1,062	989						989
Common stock dividend to parent	(703)	(681)					(703)	(681)
Issuance of common shares - dividend reinvestment and employee stock plans	132		1		76				55
Cumulative preferred dividends	(11)	(11)						(11)
Issuance of common shares - dividend reinvestment and employee stock plans (In Shares)			1,272,187						(1,538,166)
Common stock repurchases	(87)								(87)
Common stock repurchases (In Shares)									1,521,541
Other comprehensive income	(18)	(2)										(18)	(2)
BALANCE at Dec. 31, 2011	11,436	10,218	32	589	4,991	4,234	7,568	6,429	(1,033)	(64)	(64)	(58)	(8)	(962)
BALANCE (In Shares) at Dec. 31, 2011			292,888,521	235,488,094					23,194,075
Net income for common stock	1,138	1,014					1,138
NET INCOME	1,141	1,017						1,017
Common stock dividend to parent	(709)	(682)					(709)	(682)
Issuance of common shares - dividend reinvestment and employee stock plans	(1)								(4)	3
Cumulative preferred dividends	(3)	(3)						(3)
Issuance of common shares - dividend reinvestment and employee stock plans (In Shares)			(16,625)						16,625
Preferred stock redemption		3									3
Other comprehensive income	5	(1)										5	(1)
BALANCE at Dec. 31, 2012	11,869	10,552	32	589	4,991	4,234	7,997	6,761	(1,037)	(61)	(61)	(53)	(9)	(962)
BALANCE (In Shares) at Dec. 31, 2012	292,871,896	235,488,094	292,871,896	235,488,094					23,210,700
Net income for common stock	1,062	1,020					1,062
NET INCOME	1,062	1,020						1,020
Common stock dividend to parent	(721)	(728)					(721)	(728)
Issuance of common shares - dividend reinvestment and employee stock plans	7				4				3
Issuance of common shares - dividend reinvestment and employee stock plans (In Shares)			500						(500)
Other comprehensive income	28	3										28	3
BALANCE at Dec. 31, 2013	$ 12,245	$ 10,847	$ 32	$ 589	$ 4,995	$ 4,234	$ 8,338	$ 7,053	$ (1,034)	$ (61)	$ (61)	$ (25)	$ (6)	$ (962)
BALANCE (In Shares) at Dec. 31, 2013	292,872,396	235,488,094	292,872,396	235,488,094					23,210,200