Derivative Instruments and Hedging Activities (Risk Disclosures) (Details)	3 Months Ended
	Mar. 31, 2012 USD ($)	Mar. 31, 2011 USD ($)	Mar. 31, 2012 GBP (£)	Dec. 31, 2011 USD ($)	Dec. 31, 2011 GBP (£)	Mar. 31, 2011 GBP (£)
Interest Rate Risk - Cash Flow Hedges (Numeric) [Abstract]
Year of expiration of the maximum maturity date of interest rate cash flow hedge contracts	2022
Notional value of interest rate cash flow hedge contracts (excludes cross-currency contracts)	$ 175,000,000
Net notional value of PPL WEM's cross-currency cash flow hedge contracts	960,000,000
Latest maturity date of PPL WEM cross-currency cash flow hedge contracts	2021
Net notional value of PPL WW cross-currency cash flow hedge contracts	302,000,000
Latest maturity date of PPL WW cross-currency cash flow hedge contracts	2028
No or insignificant hedge ineffectiveness associated with cross-currency cash flow hedge contracts	insignificant	insignificant
No or insignificant after-tax gains (losses) previously recorded in AOCI reclassified to earnings related to interest rate cash flow hedge contracts	no such reclassifications	no such reclassifications
Net unrealized after-tax gains (losses) on interest rate cash flow hedge contracts expected to be reclassified into earnings during next 12 months	(12,000,000)
Interest Rate Risk - Fair Value Hedges (Numeric) [Abstract]
Year of expiration of the maximum maturity date of interest rate fair value hedge contracts	2047
Notional value of interest rate fair value hedges	99,000,000
No or insignificant hedge ineffectiveness associated with interest rate fair value hedges	did not recognize	did not recognize
No or insignificant gains (losses) associated with interest rate fair value hedges being excluded from the assessment of hedge effectiveness	did not recognize	did not recognize
No or insignificant gain (loss) resulting from firm commitments that no longer qualified as interest rate fair value hedges	did not recognize	did not recognize
Interest Rate Risk - Economic Activity (Numeric) [Abstract]
Notional amount of interest rate swaps classified as economic activity	179,000,000
Year of expiration of the maximum maturity date of interest rate economic activity contracts	2033
The fair value, net (asset) or liability, of interest rate swap contracts classified as economic activity	53,000,000			60,000,000
Foreign Currency Risk - Net Investment Hedges (Numeric) [Abstract]
Notional amount of net investment hedge contracts	89,000,000		55,000,000
Earliest settlement date of net investment hedge contracts	June 2012
Latest settlement date of net investment hedge contracts	September 2012
Insignificant fair value of position of net investment hedge contracts	insignificant
Fair value of net asset position of net investment hedge contracts				7,000,000
Insignificant or no net after tax gains (losses) on net investment hedges recognized in the foreign currency translation adjustment component of AOCI	insignificant	insignificant
Net after tax gains (losses) on net investment hedges included in the foreign currency translation adjustment component of AOCI	17,000,000			19,000,000
Foreign Currency Risk - Economic Activity (Numeric) [Abstract]
Total exposure hedged related to foreign currency contracts for anticipated earnings hedges classified as economic activity			761,000,000		288,000,000
Fair value of net asset or (liability) position of foreign currency contracts for anticipated earnings hedges classified as economic activity	(9,000,000)			11,000,000
Earliest termination date of foreign currency contracts for anticipated earnings hedges classified as economic activity	April 2012
Latest termination date of foreign currency contracts for anticipated earnings hedges classified as economic activity	September 2013
Gains (losses) on foreign currency contracts for anticipated earnings hedges classified as economic activity	(18,000,000)
Insignificant or no gains (losses) on foreign currency contracts for anticipated earnings hedges classified as economic activity		insignificant
Notional amount foreign currency contracts related to debt or firm commitments hedged with foreign currency contracts classified as economic activity		3,300,000,000				2,100,000,000
Gains (losses) on foreign currency contracts related to debt or commitments hedged with foreign currency contracts classified as economic activity		$ (7,000,000)