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) (Level 3 [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Net gains and losses on assets and liabilities [Abstract]
Total gains (losses) included in earnings	$ (135)	$ (8)
Energy Commodities, Net [Member] | Unregulated Wholesale Energy [Member]
Net gains and losses on assets and liabilities [Abstract]
Total gains (losses) included in earnings	(89)	(2)
Change in unrealized gains (losses) relating to positions still held at the reporting date	(13)	(2)
Energy Commodities, Net [Member] | Unregulated Retail Energy [Member]
Net gains and losses on assets and liabilities [Abstract]
Total gains (losses) included in earnings	(63)	(7)
Change in unrealized gains (losses) relating to positions still held at the reporting date	(33)	(7)
Energy Commodities, Net [Member] | Energy Purchases [Member]
Net gains and losses on assets and liabilities [Abstract]
Total gains (losses) included in earnings	17	1
Change in unrealized gains (losses) relating to positions still held at the reporting date	1	1
PPL Energy Supply LLC [Member]
Net gains and losses on assets and liabilities [Abstract]
Total gains (losses) included in earnings	(135)	(8)
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	(89)	(2)
Change in unrealized gains (losses) relating to positions still held at the reporting date	(13)	(2)
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	(63)	(7)
Change in unrealized gains (losses) relating to positions still held at the reporting date	(33)	(7)
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	17	1
Change in unrealized gains (losses) relating to positions still held at the reporting date	$ 1	$ 1