Other Postretirement Benefits (Tables) (Other Postretirement Benefits [Member])

3 Months Ended

Mar. 31, 2012

Other Postretirement Benefits [Member]

Defined Benefit Plan Disclosure [Line Items]

Net Periodic Postretirement Benefit Costs

	Con Edison						CECONY
(Millions of Dollars)	2012			2011			2012			2011
Service cost	$	7		$	6		$	5		$	5
Interest cost on accumulated other postretirement benefit obligation		18			21			16			18
Expected return on plan assets		(21	)		(22	)		(18	)		(19	)
Amortization of net actuarial loss		25			22			22			20
Amortization of prior service cost		(5	)		(2	)		(4	)		(3	)
Amortization of transition obligation		—			1			—			1
NET PERIODIC POSTRETIREMENT BENEFIT COST	$	24		$	26		$	21		$	22
Cost capitalized		(8	)		(9	)		(7	)		(8	)
Cost charged		7			4			4			3
Cost charged to operating expenses	$	23		$	21		$	18		$	17