Utility Rate Regulation (Regulatory Liabilities) (Details) - USD ($) $ in Millions		Sep. 30, 2015	Dec. 31, 2014
Regulatory Liabilities [Line Items]
Current regulatory liabilities		$ 151	$ 91
Noncurrent regulatory liabilities		962	992
Generation Supply Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		41	28
Demand Side Management [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		12	2
Gas Supply Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		9	6
Transmission Formula Rate [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		61	42
Storm Damage Expense [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		13	3
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		695	693
Coal Contracts [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	[1]	28	59
Power Purchase Agreement OVEC [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	[1]	86	92
Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		23	26
Act 129 Compliance Rider [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		25	18
Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		22	16
Interest Rate Swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		82	84
Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		15	10
Noncurrent regulatory liabilities		1	4
PPL Electric Utilities Corp [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		120	76
Noncurrent regulatory liabilities		25	18
PPL Electric Utilities Corp [Member] | Generation Supply Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		41	28
PPL Electric Utilities Corp [Member] | Transmission Formula Rate [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		61	42
PPL Electric Utilities Corp [Member] | Storm Damage Expense [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		13	3
PPL Electric Utilities Corp [Member] | Act 129 Compliance Rider [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		25	18
PPL Electric Utilities Corp [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		5	3
LG And E And KU Energy LLC [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		31	15
Noncurrent regulatory liabilities		937	974
LG And E And KU Energy LLC [Member] | Demand Side Management [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		12	2
LG And E And KU Energy LLC [Member] | Gas Supply Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		9	6
LG And E And KU Energy LLC [Member] | Gas Line Tracker [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		0	3
LG And E And KU Energy LLC [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		695	693
LG And E And KU Energy LLC [Member] | Coal Contracts [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	[1]	28	59
LG And E And KU Energy LLC [Member] | Power Purchase Agreement OVEC [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	[1]	86	92
LG And E And KU Energy LLC [Member] | Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		23	26
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		22	16
LG And E And KU Energy LLC [Member] | Interest Rate Swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		82	84
LG And E And KU Energy LLC [Member] | Fuel Adjustment Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		8	0
LG And E And KU Energy LLC [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		2	4
Noncurrent regulatory liabilities		1	4
Louisville Gas And Electric Co [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		15	10
Noncurrent regulatory liabilities		439	458
Louisville Gas And Electric Co [Member] | Demand Side Management [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		6	1
Louisville Gas And Electric Co [Member] | Gas Supply Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		9	6
Louisville Gas And Electric Co [Member] | Gas Line Tracker [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		0	3
Louisville Gas And Electric Co [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		304	302
Louisville Gas And Electric Co [Member] | Coal Contracts [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	[1]	12	25
Louisville Gas And Electric Co [Member] | Power Purchase Agreement OVEC [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	[1]	59	63
Louisville Gas And Electric Co [Member] | Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		23	24
Louisville Gas And Electric Co [Member] | Interest Rate Swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		41	42
Louisville Gas And Electric Co [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		0	2
Kentucky Utilities Co [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		16	5
Noncurrent regulatory liabilities		498	516
Kentucky Utilities Co [Member] | Demand Side Management [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		6	1
Kentucky Utilities Co [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		391	391
Kentucky Utilities Co [Member] | Coal Contracts [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	[1]	16	34
Kentucky Utilities Co [Member] | Power Purchase Agreement OVEC [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	[1]	27	29
Kentucky Utilities Co [Member] | Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		0	2
Kentucky Utilities Co [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		22	16
Kentucky Utilities Co [Member] | Interest Rate Swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities		41	42
Kentucky Utilities Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		8	0
Kentucky Utilities Co [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities		2	4
Noncurrent regulatory liabilities		$ 1	$ 2

[1] These liabilities were recorded as offsets to certain intangible assets that were recorded at fair value upon the acquisition of LKE by PPL.