Utility Rate Regulation (Regulatory Assets) (Details) - USD ($) $ in Millions		Sep. 30, 2015		Dec. 31, 2014
Regulatory Assets [Line Items]
Current regulatory assets	[1]	$ 37		$ 37
Noncurrent regulatory assets		1,627		1,562
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		4
Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		19		5
Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets		1		15
Transmission Service Charge [Member]
Regulatory Assets [Line Items]
Current regulatory assets		7		6
Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		734	[2]	720
Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		323		316
Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		101		124
Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		70		77
Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		146	[3]	122
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		130		114
Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		109		79
Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		10		11
Noncurrent regulatory assets		14		10
PPL Electric Utilities Corp [Member]
Regulatory Assets [Line Items]
Current regulatory assets		10		12
Noncurrent regulatory assets		942		897
PPL Electric Utilities Corp [Member] | Transmission Service Charge [Member]
Regulatory Assets [Line Items]
Current regulatory assets		7		6
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		411		372
PPL Electric Utilities Corp [Member] | Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		323		316
PPL Electric Utilities Corp [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		34		46
PPL Electric Utilities Corp [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		44		49
PPL Electric Utilities Corp [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		130		114
PPL Electric Utilities Corp [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		3		6
LG And E And KU Energy LLC [Member]
Regulatory Assets [Line Items]
Current regulatory assets		27		25
Noncurrent regulatory assets		685		665
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		4
LG And E And KU Energy LLC [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		19		5
LG And E And KU Energy LLC [Member] | Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets		1		15
LG And E And KU Energy LLC [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets		0		4
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		323	[2]	348
LG And E And KU Energy LLC [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		67		78
LG And E And KU Energy LLC [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		26		28
LG And E And KU Energy LLC [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		146	[3]	122
LG And E And KU Energy LLC [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		109		79
LG And E And KU Energy LLC [Member] | Plant Retirement Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		6	[4]	0
LG And E And KU Energy LLC [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		7		1
Noncurrent regulatory assets		8		10
Louisville Gas And Electric Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets		11		21
Noncurrent regulatory assets		396		397
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		3
Louisville Gas And Electric Co [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		10		4
Louisville Gas And Electric Co [Member] | Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets		1		15
Louisville Gas And Electric Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets		0		2
Louisville Gas And Electric Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		200	[2]	215
Louisville Gas And Electric Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		37		43
Louisville Gas And Electric Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		17		18
Louisville Gas And Electric Co [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		102	[3]	89
Louisville Gas And Electric Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		38		28
Louisville Gas And Electric Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		2		4
Kentucky Utilities Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets		16		4
Noncurrent regulatory assets		289		268
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		1
Kentucky Utilities Co [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets		9		1
Kentucky Utilities Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets		0		2
Kentucky Utilities Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		123	[2]	133
Kentucky Utilities Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		30		35
Kentucky Utilities Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		9		10
Kentucky Utilities Co [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		44	[3]	33
Kentucky Utilities Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		71		51
Kentucky Utilities Co [Member] | Plant Retirement Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets		6	[4]	0
Kentucky Utilities Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets		7		1
Noncurrent regulatory assets		$ 6		$ 6

[1] For PPL, these amounts are included in "Other current assets" on the Balance Sheets.

[2] Included in 2015 is $ 4 million for PPL and LKE, $ 3 million for LG&E and $ 1 million for KU related to the deferred recovery of the difference between the pension cost calculated in accordance with LG&E and KU's pension accounting policy and pension cost using a 15 ye ar amortization period for actuarial gains and losses as provided in the June 30, 2015 rate case settlement. See Note 9 and “ Kentucky Activities - Rate Case Proceedings” below for additional information.

[3] Amounts include net settlements related to forwa rd-starting interest rate swaps that were terminated in September 2015 and are included in "Cash Flows from Operating Activities" on the Statements of Cash Flows. See Note 14 for additional information.

[4] The June 30, 2015 rate case settlement provided for deferred recovery of costs associated with Green River's coal-fired generating unit retirements . These costs include inventory write-downs and separation benefits and will be amortized over three years.