Fair Value Measurements and Credit Concentration (Assets and Liabilities Measured on Recurring Basis Table) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Price risk management liabilities:
Total price risk management liabilities	$ 1,752		$ 1,244
Recurring [Member]
Assets
Cash and cash equivalents	1,256		1,102
Restricted cash and cash equivalents	491	[1]	156	[1]
Price risk management assets:
Energy commodities assets	1,417		1,188
Interest rate swaps assets	9		91
Foreign currency contracts assets	5
Total price risk management assets	1,431		1,279
NDT funds	879		864
Auction rate securities	16	[2]	19	[2]
Total assets	4,073		3,420
Price risk management liabilities:
Energy commodities liabilities	1,527		1,070
Interest rate swaps liabilities	47		36
Foreign currency contracts liabilities	123		106
Cross-currency swaps liabilities	55		32
Total price risk management liabilities	1,752		1,244
Recurring [Member] | Cash And Cash Equivalents [Member]
Price risk management assets:
NDT funds	13		14
Recurring [Member] | United States Large Cap Equity Securities [Member]
Price risk management assets:
NDT funds	556		547
Recurring [Member] | United States Mid Small Cap Equity Securities [Member]
Price risk management assets:
NDT funds	83		81
Recurring [Member] | United States Treasury Debt Securities [Member]
Price risk management assets:
NDT funds	95		95
Recurring [Member] | United States Government Sponsored Agency Debt Securities [Member]
Price risk management assets:
NDT funds	6		6
Recurring [Member] | Municipality Debt Securities [Member]
Price risk management assets:
NDT funds	80		77
Recurring [Member] | Investment Grade Corporate Debt Securities [Member]
Price risk management assets:
NDT funds	41		38
Recurring [Member] | Other Debt Securities [Member]
Price risk management assets:
NDT funds	4		5
Recurring [Member] | Receivables Payables Net [Member]
Price risk management assets:
NDT funds	1		1
Recurring [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	1,256		1,102
Restricted cash and cash equivalents	491	[1]	156	[1]
Price risk management assets:
Energy commodities assets	2		3
Interest rate swaps assets
Foreign currency contracts assets
Total price risk management assets	2		3
NDT funds	556		550
Auction rate securities
Total assets	2,305		1,811
Price risk management liabilities:
Energy commodities liabilities	1		4
Interest rate swaps liabilities
Foreign currency contracts liabilities
Cross-currency swaps liabilities
Total price risk management liabilities	1		4
Recurring [Member] | Level 1 [Member] | Cash And Cash Equivalents [Member]
Price risk management assets:
NDT funds	13		14
Recurring [Member] | Level 1 [Member] | United States Large Cap Equity Securities [Member]
Price risk management assets:
NDT funds	415		409
Recurring [Member] | Level 1 [Member] | United States Mid Small Cap Equity Securities [Member]
Price risk management assets:
NDT funds	34		33
Recurring [Member] | Level 1 [Member] | United States Treasury Debt Securities [Member]
Price risk management assets:
NDT funds	95		95
Recurring [Member] | Level 1 [Member] | United States Government Sponsored Agency Debt Securities [Member]
Price risk management assets:
NDT funds
Recurring [Member] | Level 1 [Member] | Municipality Debt Securities [Member]
Price risk management assets:
NDT funds
Recurring [Member] | Level 1 [Member] | Investment Grade Corporate Debt Securities [Member]
Price risk management assets:
NDT funds
Recurring [Member] | Level 1 [Member] | Other Debt Securities [Member]
Price risk management assets:
NDT funds
Recurring [Member] | Level 1 [Member] | Receivables Payables Net [Member]
Price risk management assets:
NDT funds	(1)		(1)
Recurring [Member] | Level 2 [Member]
Assets
Cash and cash equivalents
Restricted cash and cash equivalents
Price risk management assets:
Energy commodities assets	1,330		1,123
Interest rate swaps assets	9		91
Foreign currency contracts assets	5
Total price risk management assets	1,344		1,214
NDT funds	323		314
Auction rate securities
Total assets	1,667		1,528
Price risk management liabilities:
Energy commodities liabilities	1,458		1,028
Interest rate swaps liabilities	47		36
Foreign currency contracts liabilities	123		106
Cross-currency swaps liabilities	55		32
Total price risk management liabilities	1,683		1,202
Recurring [Member] | Level 2 [Member] | Cash And Cash Equivalents [Member]
Price risk management assets:
NDT funds
Recurring [Member] | Level 2 [Member] | United States Large Cap Equity Securities [Member]
Price risk management assets:
NDT funds	141		138
Recurring [Member] | Level 2 [Member] | United States Mid Small Cap Equity Securities [Member]
Price risk management assets:
NDT funds	49		48
Recurring [Member] | Level 2 [Member] | United States Treasury Debt Securities [Member]
Price risk management assets:
NDT funds
Recurring [Member] | Level 2 [Member] | United States Government Sponsored Agency Debt Securities [Member]
Price risk management assets:
NDT funds	6		6
Recurring [Member] | Level 2 [Member] | Municipality Debt Securities [Member]
Price risk management assets:
NDT funds	80		77
Recurring [Member] | Level 2 [Member] | Investment Grade Corporate Debt Securities [Member]
Price risk management assets:
NDT funds	41		38
Recurring [Member] | Level 2 [Member] | Other Debt Securities [Member]
Price risk management assets:
NDT funds	4		5
Recurring [Member] | Level 2 [Member] | Receivables Payables Net [Member]
Price risk management assets:
NDT funds	2		2
Recurring [Member] | Level 3 [Member]
Assets
Cash and cash equivalents
Restricted cash and cash equivalents
Price risk management assets:
Energy commodities assets	85		62
Interest rate swaps assets
Foreign currency contracts assets
Total price risk management assets	85		62
NDT funds
Auction rate securities	16	[2]	19	[2]
Total assets	101		81
Price risk management liabilities:
Energy commodities liabilities	68		38
Interest rate swaps liabilities
Foreign currency contracts liabilities
Cross-currency swaps liabilities
Total price risk management liabilities	68		38
Recurring [Member] | Level 3 [Member] | Cash And Cash Equivalents [Member]
Price risk management assets:
NDT funds
Recurring [Member] | Level 3 [Member] | United States Large Cap Equity Securities [Member]
Price risk management assets:
NDT funds
Recurring [Member] | Level 3 [Member] | United States Mid Small Cap Equity Securities [Member]
Price risk management assets:
NDT funds
Recurring [Member] | Level 3 [Member] | United States Treasury Debt Securities [Member]
Price risk management assets:
NDT funds
Recurring [Member] | Level 3 [Member] | United States Government Sponsored Agency Debt Securities [Member]
Price risk management assets:
NDT funds
Recurring [Member] | Level 3 [Member] | Municipality Debt Securities [Member]
Price risk management assets:
NDT funds
Recurring [Member] | Level 3 [Member] | Investment Grade Corporate Debt Securities [Member]
Price risk management assets:
NDT funds
Recurring [Member] | Level 3 [Member] | Other Debt Securities [Member]
Price risk management assets:
NDT funds
Recurring [Member] | Level 3 [Member] | Receivables Payables Net [Member]
Price risk management assets:
NDT funds
PPL Energy Supply LLC [Member] | Recurring [Member]
Assets
Cash and cash equivalents	441		239
Restricted cash and cash equivalents	429	[1]	85	[1]
Price risk management assets:
Energy commodities assets	1,417		1,188
Total price risk management assets	1,417		1,188
NDT funds	879		864
Auction rate securities	13	[2]	16	[2]
Total assets	3,179		2,392
Price risk management liabilities:
Energy commodities liabilities	1,527		1,070
Total price risk management liabilities	1,527		1,070
PPL Energy Supply LLC [Member] | Recurring [Member] | Cash And Cash Equivalents [Member]
Price risk management assets:
NDT funds	13		14
PPL Energy Supply LLC [Member] | Recurring [Member] | United States Large Cap Equity Securities [Member]
Price risk management assets:
NDT funds	556		547
PPL Energy Supply LLC [Member] | Recurring [Member] | United States Mid Small Cap Equity Securities [Member]
Price risk management assets:
NDT funds	83		81
PPL Energy Supply LLC [Member] | Recurring [Member] | United States Treasury Debt Securities [Member]
Price risk management assets:
NDT funds	95		95
PPL Energy Supply LLC [Member] | Recurring [Member] | United States Government Sponsored Agency Debt Securities [Member]
Price risk management assets:
NDT funds	6		6
PPL Energy Supply LLC [Member] | Recurring [Member] | Municipality Debt Securities [Member]
Price risk management assets:
NDT funds	80		77
PPL Energy Supply LLC [Member] | Recurring [Member] | Investment Grade Corporate Debt Securities [Member]
Price risk management assets:
NDT funds	41		38
PPL Energy Supply LLC [Member] | Recurring [Member] | Other Debt Securities [Member]
Price risk management assets:
NDT funds	4		5
PPL Energy Supply LLC [Member] | Recurring [Member] | Receivables Payables Net [Member]
Price risk management assets:
NDT funds	1		1
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	441		239
Restricted cash and cash equivalents	429	[1]	85	[1]
Price risk management assets:
Energy commodities assets	2		3
Total price risk management assets	2		3
NDT funds	556		550
Auction rate securities
Total assets	1,428		877
Price risk management liabilities:
Energy commodities liabilities	1		4
Total price risk management liabilities	1		4
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 1 [Member] | Cash And Cash Equivalents [Member]
Price risk management assets:
NDT funds	13		14
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 1 [Member] | United States Large Cap Equity Securities [Member]
Price risk management assets:
NDT funds	415		409
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 1 [Member] | United States Mid Small Cap Equity Securities [Member]
Price risk management assets:
NDT funds	34		33
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 1 [Member] | United States Treasury Debt Securities [Member]
Price risk management assets:
NDT funds	95		95
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 1 [Member] | United States Government Sponsored Agency Debt Securities [Member]
Price risk management assets:
NDT funds
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 1 [Member] | Municipality Debt Securities [Member]
Price risk management assets:
NDT funds
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 1 [Member] | Investment Grade Corporate Debt Securities [Member]
Price risk management assets:
NDT funds
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 1 [Member] | Other Debt Securities [Member]
Price risk management assets:
NDT funds
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 1 [Member] | Receivables Payables Net [Member]
Price risk management assets:
NDT funds	(1)		(1)
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 2 [Member]
Assets
Cash and cash equivalents
Restricted cash and cash equivalents
Price risk management assets:
Energy commodities assets	1,330		1,123
Total price risk management assets	1,330		1,123
NDT funds	323		314
Auction rate securities
Total assets	1,653		1,437
Price risk management liabilities:
Energy commodities liabilities	1,458		1,028
Total price risk management liabilities	1,458		1,028
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 2 [Member] | Cash And Cash Equivalents [Member]
Price risk management assets:
NDT funds
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 2 [Member] | United States Large Cap Equity Securities [Member]
Price risk management assets:
NDT funds	141		138
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 2 [Member] | United States Mid Small Cap Equity Securities [Member]
Price risk management assets:
NDT funds	49		48
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 2 [Member] | United States Treasury Debt Securities [Member]
Price risk management assets:
NDT funds
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 2 [Member] | United States Government Sponsored Agency Debt Securities [Member]
Price risk management assets:
NDT funds	6		6
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 2 [Member] | Municipality Debt Securities [Member]
Price risk management assets:
NDT funds	80		77
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 2 [Member] | Investment Grade Corporate Debt Securities [Member]
Price risk management assets:
NDT funds	41		38
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 2 [Member] | Other Debt Securities [Member]
Price risk management assets:
NDT funds	4		5
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 2 [Member] | Receivables Payables Net [Member]
Price risk management assets:
NDT funds	2		2
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 3 [Member]
Assets
Cash and cash equivalents
Restricted cash and cash equivalents
Price risk management assets:
Energy commodities assets	85		62
Total price risk management assets	85		62
NDT funds
Auction rate securities	13	[2]	16	[2]
Total assets	98		78
Price risk management liabilities:
Energy commodities liabilities	68		38
Total price risk management liabilities	68		38
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 3 [Member] | Cash And Cash Equivalents [Member]
Price risk management assets:
NDT funds
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 3 [Member] | United States Large Cap Equity Securities [Member]
Price risk management assets:
NDT funds
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 3 [Member] | United States Mid Small Cap Equity Securities [Member]
Price risk management assets:
NDT funds
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 3 [Member] | United States Treasury Debt Securities [Member]
Price risk management assets:
NDT funds
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 3 [Member] | United States Government Sponsored Agency Debt Securities [Member]
Price risk management assets:
NDT funds
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 3 [Member] | Municipality Debt Securities [Member]
Price risk management assets:
NDT funds
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 3 [Member] | Investment Grade Corporate Debt Securities [Member]
Price risk management assets:
NDT funds
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 3 [Member] | Other Debt Securities [Member]
Price risk management assets:
NDT funds
PPL Energy Supply LLC [Member] | Recurring [Member] | Level 3 [Member] | Receivables Payables Net [Member]
Price risk management assets:
NDT funds
PPL Electric Utilities Corp [Member] | Recurring [Member]
Assets
Cash and cash equivalents	42		25
Restricted cash and cash equivalents	1	[3]	12	[3]
Price risk management assets:
Total assets	43		37
PPL Electric Utilities Corp [Member] | Recurring [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	42		25
Restricted cash and cash equivalents	1	[3]	12	[3]
Price risk management assets:
Total assets	43		37
PPL Electric Utilities Corp [Member] | Recurring [Member] | Level 2 [Member]
Assets
Cash and cash equivalents
Restricted cash and cash equivalents
Price risk management assets:
Total assets
PPL Electric Utilities Corp [Member] | Recurring [Member] | Level 3 [Member]
Assets
Cash and cash equivalents
Restricted cash and cash equivalents
Price risk management assets:
Total assets
LG And E And KU Energy LLC [Member] | Recurring [Member]
Assets
Cash and cash equivalents	30		35
Restricted cash and cash equivalents	21	[4]	22	[4]
Price risk management assets:
Total price risk management assets
Total assets	51		57
Price risk management liabilities:
Interest rate swaps liabilities	40		36
Total price risk management liabilities	40		36
LG And E And KU Energy LLC [Member] | Recurring [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	30		35
Restricted cash and cash equivalents	21	[4]	22	[4]
Price risk management assets:
Total price risk management assets
Total assets	51		57
Price risk management liabilities:
Interest rate swaps liabilities
Total price risk management liabilities
LG And E And KU Energy LLC [Member] | Recurring [Member] | Level 2 [Member]
Assets
Cash and cash equivalents
Restricted cash and cash equivalents
Price risk management assets:
Total price risk management assets
Total assets
Price risk management liabilities:
Interest rate swaps liabilities	40		36
Total price risk management liabilities	40		36
LG And E And KU Energy LLC [Member] | Recurring [Member] | Level 3 [Member]
Assets
Cash and cash equivalents
Restricted cash and cash equivalents
Price risk management assets:
Total price risk management assets
Total assets
Price risk management liabilities:
Interest rate swaps liabilities
Total price risk management liabilities
Louisville Gas And Electric Co [Member] | Recurring [Member]
Assets
Cash and cash equivalents	9		8
Restricted cash and cash equivalents	21	[4]	22	[4]
Price risk management assets:
Total price risk management assets
Total assets	30		30
Price risk management liabilities:
Interest rate swaps liabilities	40		36
Total price risk management liabilities	40		36
Louisville Gas And Electric Co [Member] | Recurring [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	9		8
Restricted cash and cash equivalents	21	[4]	22	[4]
Price risk management assets:
Total price risk management assets
Total assets	30		30
Price risk management liabilities:
Interest rate swaps liabilities
Total price risk management liabilities
Louisville Gas And Electric Co [Member] | Recurring [Member] | Level 2 [Member]
Assets
Cash and cash equivalents
Restricted cash and cash equivalents
Price risk management assets:
Total price risk management assets
Total assets
Price risk management liabilities:
Interest rate swaps liabilities	40		36
Total price risk management liabilities	40		36
Louisville Gas And Electric Co [Member] | Recurring [Member] | Level 3 [Member]
Assets
Cash and cash equivalents
Restricted cash and cash equivalents
Price risk management assets:
Total price risk management assets
Total assets
Price risk management liabilities:
Interest rate swaps liabilities
Total price risk management liabilities
Kentucky Utilities Co [Member] | Recurring [Member]
Assets
Cash and cash equivalents	21		21
Price risk management assets:
Total price risk management assets
Total assets	21		21
Kentucky Utilities Co [Member] | Recurring [Member] | Level 1 [Member]
Assets
Cash and cash equivalents	21		21
Price risk management assets:
Total price risk management assets
Total assets	21		21
Kentucky Utilities Co [Member] | Recurring [Member] | Level 2 [Member]
Assets
Cash and cash equivalents
Price risk management assets:
Total price risk management assets
Total assets
Kentucky Utilities Co [Member] | Recurring [Member] | Level 3 [Member]
Assets
Cash and cash equivalents
Price risk management assets:
Total price risk management assets
Total assets

[1] Current portion is included in "Restricted cash and cash equivalents" and long-term portion is included in "Other noncurrent assets" on the Balance Sheets.

[2] Included in "Other investments" on the Balance Sheets.

[3] Current portion is included in "Other current assets" and long-term portion is included in "Other noncurrent assets" on the Balance Sheets.

[4] Included in "Other noncurrent assets" on the Balance Sheets.