Consolidated Statement of Statement/Shareholders' Equity - USD ($) shares in Millions	Total	CECONY	Common Stock	Common Stock CECONY	Additional Paid-In Capital	Additional Paid-In Capital CECONY	Retained Earnings	Retained Earnings CECONY	Repurchased Con Edison Stock CECONY	Treasury Stock	Capital Stock Expense	Capital Stock Expense CECONY	Accumulated Other Comprehensive Income/(Loss)	Accumulated Other Comprehensive Income/(Loss) CECONY	Noncontrolling Interest
BALANCE at Dec. 31, 2012	$ 11,869,000,000		$ 32,000,000		$ 4,991,000,000		$ 7,997,000,000			$ (1,037,000,000)	$ (61,000,000)		$ (53,000,000)
BALANCE at Dec. 31, 2012		$ 10,552,000,000		$ 589,000,000		$ 4,234,000,000		$ 6,761,000,000	$ (962,000,000)			$ (61,000,000)		$ (9,000,000)
BALANCE (in shares) at Dec. 31, 2012			293	235						23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,062,000,000	1,020,000,000					1,062,000,000	1,020,000,000
Common stock dividends	(721,000,000)	(728,000,000)					(721,000,000)	(728,000,000)
Issuance of common shares for stock plans, net of repurchases	7,000,000				4,000,000					$ 3,000,000
Issuance of common shares for stock plans, net of repurchases (in shares)			0							0
Other comprehensive income (loss)	28,000,000	3,000,000											28,000,000	3,000,000
BALANCE at Dec. 31, 2013		10,847,000,000		$ 589,000,000		4,234,000,000		7,053,000,000	(962,000,000)			(61,000,000)		(6,000,000)
BALANCE at Dec. 31, 2013	12,245,000,000		$ 32,000,000		4,995,000,000		8,338,000,000			$ (1,034,000,000)	$ (61,000,000)		(25,000,000)		$ 0
BALANCE (in shares) at Dec. 31, 2013			293	235						23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,092,000,000	1,058,000,000					1,092,000,000	1,058,000,000
Common stock dividends	(739,000,000)	(712,000,000)					(739,000,000)	(712,000,000)
Issuance of common shares for stock plans, net of repurchases	(2,000,000)				(4,000,000)					$ 2,000,000
Issuance of common shares for stock plans, net of repurchases (in shares)			0							0
Other comprehensive income (loss)	(20,000,000)	(5,000,000)											(20,000,000)	(5,000,000)
BALANCE at Dec. 31, 2014	12,576,000,000	$ 11,188,000,000		$ 589,000,000		4,234,000,000		7,399,000,000	(962,000,000)			(61,000,000)		(11,000,000)
BALANCE at Dec. 31, 2014	$ 12,585,000,000		$ 32,000,000		4,991,000,000		8,691,000,000			$ (1,032,000,000)	(61,000,000)		(45,000,000)		9,000,000
BALANCE (in shares) at Dec. 31, 2014	293	235	293	235						23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Noncontrolling interest	$ 9,000,000														9,000,000
Net income	1,193,000,000	$ 1,084,000,000					1,193,000,000	1,084,000,000
Common stock dividends	(761,000,000)	(872,000,000)					(761,000,000)	(872,000,000)
Capital contribution by parent		13,000,000				13,000,000
Issuance of common shares for stock plans, net of repurchases	33,000,000				39,000,000					$ (6,000,000)
Issuance of common shares for stock plans, net of repurchases (in shares)			0							0
Other comprehensive income (loss)	11,000,000	2,000,000											11,000,000	2,000,000
BALANCE at Dec. 31, 2015	13,052,000,000	$ 11,415,000,000		$ 589,000,000		$ 4,247,000,000		$ 7,611,000,000	$ (962,000,000)			$ (61,000,000)		$ (9,000,000)
BALANCE at Dec. 31, 2015	$ 13,061,000,000		$ 32,000,000		$ 5,030,000,000		$ 9,123,000,000			$ (1,038,000,000)	$ (61,000,000)		$ (34,000,000)		9,000,000
BALANCE (in shares) at Dec. 31, 2015	293	235	293	235						23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Noncontrolling interest	$ 9,000,000														$ 9,000,000