Fair Value Measurements and Credit Concentration (Net Asset and Liability Measured on Recurring Basis Level 3 Unobservable Inputs Reconciliation Rollforward) (Details) (Recurring [Member], Level 3 [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014		Jun. 30, 2013
Reconciliation of net assets and liabilities
Balance at beginning of period	$ 33	$ 30	$ 43		$ 39
Total realized/unrealized gains (losses)
Included in earnings	72	14	(63)		6
Included in OCI			(1)	[1]	3	[1]
Purchases	(6)		(6)
Sales		(2)	(3)		(2)
Settlements	(9)	4	119		3
Transfers into Level 3		12			13
Transfers out of Level 3		4	1
Balance at end of period	90	62	90		62
Energy Commodities, Net [Member]
Reconciliation of net assets and liabilities
Balance at beginning of period	17	14	24		22
Total realized/unrealized gains (losses)
Included in earnings	72	14	(63)		6
Included in OCI
Purchases	(6)		(6)
Sales		(2)			(2)
Settlements	(9)	4	119		3
Transfers into Level 3		6			7
Transfers out of Level 3		4			4
Balance at end of period	74	40	74		40
Auction Rate Securities [Member]
Reconciliation of net assets and liabilities
Balance at beginning of period	16	16	19		16
Total realized/unrealized gains (losses)
Included in earnings
Included in OCI
Purchases
Sales			(3)
Settlements
Transfers into Level 3		3			3
Transfers out of Level 3
Balance at end of period	16	19	16		19
Cross Currency Swaps [Member]
Reconciliation of net assets and liabilities
Balance at beginning of period					1
Total realized/unrealized gains (losses)
Included in earnings
Included in OCI			(1)	[1]	3	[1]
Purchases
Sales
Settlements
Transfers into Level 3		3			3
Transfers out of Level 3			1		(4)
Balance at end of period		3			3
PPL Energy Supply LLC [Member]
Reconciliation of net assets and liabilities
Balance at beginning of period	30	27	40		35
Total realized/unrealized gains (losses)
Included in earnings	72	14	(63)		6
Purchases	(6)		(6)
Sales		(2)	(3)		(2)
Settlements	(9)	4	119		3
Transfers into Level 3		9			10
Transfers out of Level 3		4			4
Balance at end of period	87	56	87		56
PPL Energy Supply LLC [Member] | Energy Commodities, Net [Member]
Reconciliation of net assets and liabilities
Balance at beginning of period	17	14	24		22
Total realized/unrealized gains (losses)
Included in earnings	72	14	(63)		6
Purchases	(6)		(6)
Sales		(2)			(2)
Settlements	(9)	4	119		3
Transfers into Level 3		6			7
Transfers out of Level 3		4			4
Balance at end of period	74	40	74		40
PPL Energy Supply LLC [Member] | Auction Rate Securities [Member]
Reconciliation of net assets and liabilities
Balance at beginning of period	13	13	16		13
Total realized/unrealized gains (losses)
Included in earnings
Purchases
Sales			(3)
Settlements
Transfers into Level 3		3			3
Transfers out of Level 3
Balance at end of period	$ 13	$ 16	$ 13		$ 16

[1] "Energy Commodities, net" and "Cross-Currency Swaps" are included in "Qualifying derivatives" and "Auction Rate Securities" are included in "Available-for-sale securities" on the Statements of Comprehensive Income.