Utility Rate Regulation (Regulatory Assets and Liabilities) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Regulatory Assets [Line Items]
Current regulatory assets	$ 33		$ 19
Noncurrent regulatory assets	1,246		1,483
Regulatory Liabilities [Line Items]
Current regulatory liabilities	90		61
Noncurrent regulatory liabilities	1,048		1,010
Regulatory Assets And Liabilities [Line Items]
Regulatory liability for deferred costs not yet approved by regulators	14
Regulatory Assets and Liabilities - Act 129 Compliance Rider (Numeric) [Abstract]
Maximum recoverable cost			250
Regulatory Assets and Liabilities - Environmental Cost Recovery (Numeric) [Abstract]
Return on equity for approved projects remaining from earlier ECR plans	10.25%
Return on equity for approved projects in the 2009 ECR proceedings			10.63%		10.63%
Return on equity for approved projects in the 2011 ECR proceedings			10.10%		10.10%
Defined Benefit Plan Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Dec. 31, 2014
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory asset costs expected to be amortized into net periodic defined benefit costs in the next year	28
Unamortized Loss On Debt Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Dec. 31, 2040
Accumulated Cost Of Removal Of Utility Plant Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period	five-year
Act 129 Compliance Rider Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period	three-year
Amortization end date	May 31, 2016		May 31, 2013
Regulatory Assets and Liabilities - Act 129 Compliance Rider (Numeric) [Abstract]
Maximum recoverable cost Phase II	185
Environmental Cost Recovery Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period	within 12 months
Period of recurring reviews of activity	six-month
Period of when rider amounts are rolled into base rates	two-year
Gas Supply Clause Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period	within 18 months
Fuel Adjustments Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period	within 12 months
Period of recurring reviews of activity	six-month
Period of when rider amounts are rolled into base rates	two-year
Interest Rate Swaps Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Dec. 31, 2033
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Principal amount of debt related to interest rate swap that is receiving regulatory accounting treatment	500
Realized gains (losses) recognized during period that is receiving regulatory accounting treatment	86
Amortization end date for 2008 terminated swap contract	Dec. 31, 2035
Gas Line Tracker Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Return on equity	10.25%
Coal Contracts Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Dec. 31, 2016
Power Purchase Agreement Ohio Valley Electric Corporation Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Mar. 31, 2026
LGE [Member]
Regulatory Assets and Liabilities - Gas Line Tracker (Numeric) [Abstract]
Term, in years, of the gas service rider program	5
Generation Supply Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	23		27
Environmental Cost Recovery [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities			4
Gas Supply Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3		4
Gas Line Tracker [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	6
Transmission Service Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	8		6
Transmission Formula Rate [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	20
Fuel Adjustment Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	4		1
Universal Service Rider [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	10		17
Storm Damage Expense [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	14
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	688		679
Coal Contracts [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	98	[1]	141	[1]
Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	100	[1]	108	[1]
Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	30		34
Act 129 Compliance Rider [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	15		8
Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	26		17
Interest Rate Swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	86		14
Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	2		2
Noncurrent regulatory liabilities	5		9
Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	10		11
Fuel Adjustment Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	2		6
Demand Side Management [Member]
Regulatory Assets [Line Items]
Current regulatory assets	8		1
Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	509		730
Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	306		293
Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	147		168
Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	85		96
Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	44		67
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	98		71
Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	44		26
Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets	7		1
Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	6
Noncurrent regulatory assets	13		32
PPL Electric Utilities Corp [Member]
Regulatory Assets [Line Items]
Current regulatory assets	6
Noncurrent regulatory assets	772		853
Regulatory Liabilities [Line Items]
Current regulatory liabilities	76		52
Noncurrent regulatory liabilities	15		8
Regulatory Assets And Liabilities [Line Items]
Regulatory liability for deferred costs not yet approved by regulators	14
Regulatory Assets and Liabilities - Act 129 Compliance Rider (Numeric) [Abstract]
Maximum recoverable cost			250
PPL Electric Utilities Corp [Member] | Defined Benefit Plan Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Dec. 31, 2014
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory asset costs expected to be amortized into net periodic defined benefit costs in the next year	9
PPL Electric Utilities Corp [Member] | Unamortized Loss On Debt Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Dec. 31, 2029
PPL Electric Utilities Corp [Member] | Accumulated Cost Of Removal Of Utility Plant Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period	five-year
PPL Electric Utilities Corp [Member] | Act 129 Compliance Rider Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period	three-year
Amortization end date	May 31, 2016		May 31, 2013
Regulatory Assets and Liabilities - Act 129 Compliance Rider (Numeric) [Abstract]
Maximum recoverable cost Phase II	185
PPL Electric Utilities Corp [Member] | Generation Supply Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	23		27
PPL Electric Utilities Corp [Member] | Transmission Service Charge [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	8		6
PPL Electric Utilities Corp [Member] | Transmission Formula Rate [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	20
PPL Electric Utilities Corp [Member] | Universal Service Rider [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	10		17
PPL Electric Utilities Corp [Member] | Storm Damage Expense [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	14
PPL Electric Utilities Corp [Member] | Act 129 Compliance Rider [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	15		8
PPL Electric Utilities Corp [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	1		2
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	257		362
PPL Electric Utilities Corp [Member] | Taxes Recoverable Through Future Rates [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	306		293
PPL Electric Utilities Corp [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	53		59
PPL Electric Utilities Corp [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	57		65
PPL Electric Utilities Corp [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	98		71
PPL Electric Utilities Corp [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets	6
Noncurrent regulatory assets	1		3
LG And E And KU Energy LLC [Member]
Regulatory Assets [Line Items]
Current regulatory assets	27		19
Noncurrent regulatory assets	474		630
Regulatory Liabilities [Line Items]
Current regulatory liabilities	14		9
Noncurrent regulatory liabilities	1,033		1,002
Regulatory Assets and Liabilities - Environmental Cost Recovery (Numeric) [Abstract]
Return on equity for approved projects remaining from earlier ECR plans	10.25%
Return on equity for approved projects in the 2009 ECR proceedings			10.63%		10.63%
Return on equity for approved projects in the 2011 ECR proceedings			10.10%		10.10%
LG And E And KU Energy LLC [Member] | Defined Benefit Plan Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Dec. 31, 2014
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory asset costs expected to be amortized into net periodic defined benefit costs in the next year	19
LG And E And KU Energy LLC [Member] | Unamortized Loss On Debt Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Dec. 31, 2040
LG And E And KU Energy LLC [Member] | Environmental Cost Recovery Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period	within 12 months
Period of recurring reviews of activity	six-month
Period of when rider amounts are rolled into base rates	two-year
LG And E And KU Energy LLC [Member] | Gas Supply Clause Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period	within 18 months
LG And E And KU Energy LLC [Member] | Fuel Adjustments Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period	within 12 months
Period of recurring reviews of activity	six-month
Period of when rider amounts are rolled into base rates	two-year
LG And E And KU Energy LLC [Member] | Interest Rate Swaps Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Dec. 31, 2033
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Principal amount of debt related to interest rate swap that is receiving regulatory accounting treatment	500
Realized gains (losses) recognized during period that is receiving regulatory accounting treatment	86
Amortization end date for 2008 terminated swap contract	Dec. 31, 2035
LG And E And KU Energy LLC [Member] | Gas Line Tracker Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Return on equity	10.25%
LG And E And KU Energy LLC [Member] | Coal Contracts Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Dec. 31, 2016
LG And E And KU Energy LLC [Member] | Power Purchase Agreement Ohio Valley Electric Corporation Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Mar. 31, 2026
LG And E And KU Energy LLC [Member] | LGE [Member]
Regulatory Assets and Liabilities - Gas Line Tracker (Numeric) [Abstract]
Term, in years, of the gas service rider program	5
LG And E And KU Energy LLC [Member] | Environmental Cost Recovery [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities			4
LG And E And KU Energy LLC [Member] | Gas Supply Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3		4
LG And E And KU Energy LLC [Member] | Gas Line Tracker [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	6
LG And E And KU Energy LLC [Member] | Fuel Adjustment Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	4		1
LG And E And KU Energy LLC [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	688		679
LG And E And KU Energy LLC [Member] | Coal Contracts [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	98	[1]	141	[1]
LG And E And KU Energy LLC [Member] | Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	100	[1]	108	[1]
LG And E And KU Energy LLC [Member] | Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	30		34
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	26		17
LG And E And KU Energy LLC [Member] | Interest Rate Swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	86		14
LG And E And KU Energy LLC [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	1
Noncurrent regulatory liabilities	5		9
LG And E And KU Energy LLC [Member] | Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	10		11
LG And E And KU Energy LLC [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	2		6
LG And E And KU Energy LLC [Member] | Demand Side Management [Member]
Regulatory Assets [Line Items]
Current regulatory assets	8		1
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	252		368
LG And E And KU Energy LLC [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	94		109
LG And E And KU Energy LLC [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	28		31
LG And E And KU Energy LLC [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	44		67
LG And E And KU Energy LLC [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	44		26
LG And E And KU Energy LLC [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets	7		1
LG And E And KU Energy LLC [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	12		29
Louisville Gas And Electric Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets	17		19
Noncurrent regulatory assets	303		400
Regulatory Liabilities [Line Items]
Current regulatory liabilities	9		4
Noncurrent regulatory liabilities	482		471
Regulatory Assets and Liabilities - Environmental Cost Recovery (Numeric) [Abstract]
Return on equity for approved projects remaining from earlier ECR plans	10.25%
Return on equity for approved projects in the 2009 ECR proceedings			10.63%		10.63%
Return on equity for approved projects in the 2011 ECR proceedings			10.10%		10.10%
Regulatory Assets and Liabilities - Gas Line Tracker (Numeric) [Abstract]
Term, in years, of the gas service rider program	5
Louisville Gas And Electric Co [Member] | Defined Benefit Plan Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Dec. 31, 2014
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory asset costs expected to be amortized into net periodic defined benefit costs in the next year	13
Louisville Gas And Electric Co [Member] | Unamortized Loss On Debt Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Dec. 31, 2035
Louisville Gas And Electric Co [Member] | Environmental Cost Recovery Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period	within 12 months
Period of recurring reviews of activity	six-month
Period of when rider amounts are rolled into base rates	two-year
Louisville Gas And Electric Co [Member] | Gas Supply Clause Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period	within 18 months
Louisville Gas And Electric Co [Member] | Fuel Adjustments Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period	within 12 months
Period of recurring reviews of activity	six-month
Period of when rider amounts are rolled into base rates	two-year
Louisville Gas And Electric Co [Member] | Interest Rate Swaps Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Dec. 31, 2033
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Principal amount of debt related to interest rate swap that is receiving regulatory accounting treatment	250
Realized gains (losses) recognized during period that is receiving regulatory accounting treatment	43
Amortization end date for 2008 terminated swap contract	Dec. 31, 2035
Louisville Gas And Electric Co [Member] | Gas Line Tracker Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Return on equity	10.25%
Louisville Gas And Electric Co [Member] | Coal Contracts Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Dec. 31, 2016
Louisville Gas And Electric Co [Member] | Power Purchase Agreement Ohio Valley Electric Corporation Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Mar. 31, 2026
Louisville Gas And Electric Co [Member] | Gas Supply Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	3		4
Louisville Gas And Electric Co [Member] | Gas Line Tracker [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	6
Louisville Gas And Electric Co [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	299		297
Louisville Gas And Electric Co [Member] | Coal Contracts [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	43	[1]	61	[1]
Louisville Gas And Electric Co [Member] | Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	69	[1]	75	[1]
Louisville Gas And Electric Co [Member] | Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	26		28
Louisville Gas And Electric Co [Member] | Interest Rate Swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	43		7
Louisville Gas And Electric Co [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities
Noncurrent regulatory liabilities	2		3
Louisville Gas And Electric Co [Member] | Gas Supply Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	10		11
Louisville Gas And Electric Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets [Line Items]
Current regulatory assets	2		6
Louisville Gas And Electric Co [Member] | Demand Side Management [Member]
Regulatory Assets [Line Items]
Current regulatory assets	3		1
Louisville Gas And Electric Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	164		232
Louisville Gas And Electric Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	51		59
Louisville Gas And Electric Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	18		20
Louisville Gas And Electric Co [Member] | Interest Rate Swaps [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	44		67
Louisville Gas And Electric Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	21		15
Louisville Gas And Electric Co [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets	2		1
Louisville Gas And Electric Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	5		7
Kentucky Utilities Co [Member]
Regulatory Assets [Line Items]
Current regulatory assets	10
Noncurrent regulatory assets	171		230
Regulatory Liabilities [Line Items]
Current regulatory liabilities	5		5
Noncurrent regulatory liabilities	551		531
Regulatory Assets and Liabilities - Environmental Cost Recovery (Numeric) [Abstract]
Return on equity for approved projects remaining from earlier ECR plans	10.25%
Return on equity for approved projects in the 2009 ECR proceedings			10.63%		10.63%
Return on equity for approved projects in the 2011 ECR proceedings			10.10%		10.10%
Kentucky Utilities Co [Member] | Defined Benefit Plan Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Dec. 31, 2014
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory asset costs expected to be amortized into net periodic defined benefit costs in the next year	6
Kentucky Utilities Co [Member] | Unamortized Loss On Debt Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization end date	Dec. 31, 2040
Kentucky Utilities Co [Member] | Environmental Cost Recovery Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period	within 12 months
Period of recurring reviews of activity	six-month
Period of when rider amounts are rolled into base rates	two-year
Kentucky Utilities Co [Member] | Gas Supply Clause Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period	within 18 months
Kentucky Utilities Co [Member] | Fuel Adjustments Combined Asset And Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Amortization period	within 12 months
Period of recurring reviews of activity	six-month
Period of when rider amounts are rolled into base rates	two-year
Kentucky Utilities Co [Member] | Interest Rate Swaps Combined Asset And Liability [Member]
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Principal amount of debt related to interest rate swap that is receiving regulatory accounting treatment	250
Realized gains (losses) recognized during period that is receiving regulatory accounting treatment	43
Kentucky Utilities Co [Member] | Environmental Cost Recovery [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities			4
Kentucky Utilities Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	4		1
Kentucky Utilities Co [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	389		382
Kentucky Utilities Co [Member] | Coal Contracts [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	55	[1]	80	[1]
Kentucky Utilities Co [Member] | Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	31	[1]	33	[1]
Kentucky Utilities Co [Member] | Net Deferred Tax Assets [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	4		6
Kentucky Utilities Co [Member] | Defined Benefit Plans [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	26		17
Kentucky Utilities Co [Member] | Interest Rate Swaps [Member]
Regulatory Liabilities [Line Items]
Noncurrent regulatory liabilities	43		7
Kentucky Utilities Co [Member] | Other Regulatory Liabilities [Member]
Regulatory Liabilities [Line Items]
Current regulatory liabilities	1
Noncurrent regulatory liabilities	3		6
Kentucky Utilities Co [Member] | Demand Side Management [Member]
Regulatory Assets [Line Items]
Current regulatory assets	5
Kentucky Utilities Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	88		136
Kentucky Utilities Co [Member] | Storm Costs [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	43		50
Kentucky Utilities Co [Member] | Unamortized Loss On Debt [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	10		11
Kentucky Utilities Co [Member] | Asset Retirement Obligations [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	23		11
Kentucky Utilities Co [Member] | Environmental Cost Recovery [Member]
Regulatory Assets [Line Items]
Current regulatory assets	5
Kentucky Utilities Co [Member] | Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Noncurrent regulatory assets	$ 7		$ 22

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