Fair Value Measurements and Credit Concentration (Net Asset and Liability Measured on Recurring Basis Level 3 Gain Loss Included in Earnings and Other Recurring Numeric Data) (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
Net gains and losses on assets and liabilities [Abstract]
Total gains (losses) included in earnings	$ 72	$ 14	$ (63)	$ 6
Energy Commodities, Net [Member] | Unregulated Wholesale Energy [Member]
Net gains and losses on assets and liabilities [Abstract]
Total gains (losses) included in earnings	58	(7)	(31)	(9)
Change in unrealized gains (losses) relating to positions still held at the reporting date	47	(7)	44	(9)
Energy Commodities, Net [Member] | Unregulated Retail Energy [Member]
Net gains and losses on assets and liabilities [Abstract]
Total gains (losses) included in earnings	12	22	(51)	15
Change in unrealized gains (losses) relating to positions still held at the reporting date	10	22	(21)	17
Energy Commodities, Net [Member] | Energy Purchases [Member]
Net gains and losses on assets and liabilities [Abstract]
Total gains (losses) included in earnings	2	(1)	19
Change in unrealized gains (losses) relating to positions still held at the reporting date	(4)	1	(3)	2
PPL Energy Supply LLC [Member]
Net gains and losses on assets and liabilities [Abstract]
Total gains (losses) included in earnings	72	14	(63)	6
PPL Energy Supply LLC [Member] | Energy Commodities, Net [Member] | Unregulated Wholesale Energy [Member]
Net gains and losses on assets and liabilities [Abstract]
Total gains (losses) included in earnings	58	(7)	(31)	(9)
Change in unrealized gains (losses) relating to positions still held at the reporting date	47	(7)	44	(9)
PPL Energy Supply LLC [Member] | Energy Commodities, Net [Member] | Unregulated Retail Energy [Member]
Net gains and losses on assets and liabilities [Abstract]
Total gains (losses) included in earnings	12	22	(51)	15
Change in unrealized gains (losses) relating to positions still held at the reporting date	10	22	(21)	17
PPL Energy Supply LLC [Member] | Energy Commodities, Net [Member] | Energy Purchases [Member]
Net gains and losses on assets and liabilities [Abstract]
Total gains (losses) included in earnings	2	(1)	19
Change in unrealized gains (losses) relating to positions still held at the reporting date	$ (4)	$ 1	$ (3)	$ 2