Fair Value Measurements (Details 1) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012
NUG contracts
Reconciliation of changes in the fair value of NUG contracts
Terminations, Derivative Assets	$ 0	[1]
Terminations, Derivative Liability	0	[1]
Terminations, Net	0	[1]
Level 3 | NUG contracts
Reconciliation of changes in the fair value of NUG contracts
Beginning Balance, Derivative Assets	36	[1]	57	[1]
Beginning Balance, Derivative Liabilities	(290)	[1]	(349)	[1]
Beginning Balance, Net	(254)	[1]	(292)	[1]
Unrealized gain (loss), Derivative Assets	(8)	[1]	(20)	[1]
Unrealized gain (loss), Derivative Liabilities	(17)	[1]	(180)	[1]
Unrealized gain (loss), Net	(25)	[1]	(200)	[1]
Purchases, Derivative Assets	0	[1]	0	[1]
Purchases, Derivative Liabilities	0	[1]	0	[1]
Purchases, Net	0	[1]	0	[1]
Settlements, Derivative Assets	(8)	[1]	(1)	[1]
Settlements, Derivative Liabilities	85	[1]	239	[1]
Settlements, Net	77	[1]	238	[1]
Ending Balance, Derivative Assets	20	[1]	36	[1]
Ending Balance, Derivative Liabilities	(222)	[1]	(290)	[1]
Ending Balance, Net	(202)	[1]	(254)	[1]
Level 3 | LCAPP Contracts
Reconciliation of changes in the fair value of NUG contracts
Beginning Balance, Derivative Assets	0	[1]	0	[1]
Beginning Balance, Derivative Liabilities	(144)	[1]	0	[1]
Beginning Balance, Net	(144)	[1]	0	[1]
Unrealized gain (loss), Derivative Assets	0	[1]	0	[1]
Unrealized gain (loss), Derivative Liabilities	(22)	[1]	1	[1]
Unrealized gain (loss), Net	(22)	[1]	1	[1]
Purchases, Derivative Assets	0	[1]	0	[1]
Purchases, Derivative Liabilities	0	[1]	(145)	[1]
Purchases, Net	0	[1]	(145)	[1]
Terminations, Derivative Assets	0	[1]
Terminations, Derivative Liability	166	[1]
Terminations, Net	166	[1]
Settlements, Derivative Assets	0	[1]	0	[1]
Settlements, Derivative Liabilities	0	[1]	0	[1]
Settlements, Net	0	[1]	0	[1]
Ending Balance, Derivative Assets	0	[1]	0	[1]
Ending Balance, Derivative Liabilities	0	[1]	(144)	[1]
Ending Balance, Net	0	[1]	(144)	[1]
Level 3 | FTRs
Reconciliation of changes in the fair value of NUG contracts
Beginning Balance, Derivative Assets	8		1
Beginning Balance, Derivative Liabilities	(9)		(23)
Beginning Balance, Net	(1)		(22)
Unrealized gain (loss), Derivative Assets	3		6
Unrealized gain (loss), Derivative Liabilities	1		(6)
Unrealized gain (loss), Net	4		0
Purchases, Derivative Assets	6		13
Purchases, Derivative Liabilities	(15)		(10)
Purchases, Net	(9)		3
Terminations, Derivative Assets	0
Terminations, Derivative Liability	0
Terminations, Net	0
Settlements, Derivative Assets	(13)		(12)
Settlements, Derivative Liabilities	11		30
Settlements, Net	(2)		18
Ending Balance, Derivative Assets	4		8
Ending Balance, Derivative Liabilities	(12)		(9)
Ending Balance, Net	(8)		(1)
FES | Level 3 | FTRs
Reconciliation of changes in the fair value of NUG contracts
Beginning Balance, Derivative Assets	6		1
Beginning Balance, Derivative Liabilities	(6)		(7)
Beginning Balance, Net	0		(6)
Unrealized gain (loss), Derivative Assets	0		4
Unrealized gain (loss), Derivative Liabilities	(2)		(4)
Unrealized gain (loss), Net	(2)		0
Purchases, Derivative Assets	5		9
Purchases, Derivative Liabilities	(12)		(7)
Purchases, Net	(7)		2
Settlements, Derivative Assets	(8)		(8)
Settlements, Derivative Liabilities	9		12
Settlements, Net	1		4
Ending Balance, Derivative Assets	3		6
Ending Balance, Derivative Liabilities	(11)		(6)
Ending Balance, Net	$ (8)		$ 0

[1] Changes in the fair value of NUG and LCAPP contracts are generally subject to regulatory accounting treatment and do not impact earnings.