Income and Other Taxes (Unrecognized to End) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 Integer		Dec. 31, 2011		Dec. 31, 2010
Unrecognized Tax Benefits (Details) [Roll Forward]
Beginning of period	$ 145		$ 251
Additions based on tax positions of prior years	15		40
Reductions based on tax positions of prior years	(61)		(160)
Additions based on tax positions related to the current year	7		25
Reductions based on tax positions related to the current year	(3)		(4)
Settlements	(2)
Lapse of applicable statute of limitation	(9)		(10)
Effects of foreign currency translation			3
End of period	92		145		251
Unrecognized Tax Benefits - Probable Increase (Decrease) Next 12 Months (Details) [Abstract]
Total amount unrecognized tax benefits may increase in next 12 months	10
Total amount unrecognized tax benefits may decrease in next 12 months	90
Total unrecognized tax benefits and related effects that, if recognized, would decrease the effective tax rate	38		41
Open Tax Positions - Accrued Interest (Numeric) [Abstract]
Accrued interest receivable (payable) related to tax positions	(16)		(20)
Open Tax Positions - Interest and Penalties (Numeric) [Abstract]
Interest expense (benefit) related to tax positions	(4)		27		(39)
Income Tax Examination (Details) [Line Items]
Number of major tax jurisdictions tax returns are filed	5
Tax Legislation (Numeric) [Abstract]
Bonus depreciation expensing provision for qualifying property	50.00%
US - Federal [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	1997 and prior
Pennsylvania - State [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2008 and prior
Kentucky - State [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2008 and prior
Montana - State [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2008 and prior
United Kingdom - Foreign [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2010 and prior
PPL Energy Supply LLC [Member]
Unrecognized Tax Benefits (Details) [Roll Forward]
Beginning of period	28		183
Additions based on tax positions of prior years	4		1
Reductions based on tax positions of prior years	(2)
Reductions based on tax positions related to the current year			(1)
Derecognize unrecognized tax benefits			(155)	[1]
End of period	30		28		183
Unrecognized Tax Benefits - Probable Increase (Decrease) Next 12 Months (Details) [Abstract]
Total amount unrecognized tax benefits may increase in next 12 months	1
Total amount unrecognized tax benefits may decrease in next 12 months	30
Total unrecognized tax benefits and related effects that, if recognized, would decrease the effective tax rate	13		13
Open Tax Positions - Accrued Interest (Numeric) [Abstract]
Accrued interest receivable (payable) related to tax positions	17		2
Open Tax Positions - Interest and Penalties (Numeric) [Abstract]
Interest expense (benefit) related to tax positions	(4)		6		(30)
Income Tax Examination (Details) [Line Items]
Number of major tax jurisdictions tax returns are filed	3
Tax Legislation (Numeric) [Abstract]
Bonus depreciation expensing provision for qualifying property	50.00%
PPL Energy Supply LLC [Member] | US - Federal [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	1997 and prior
PPL Energy Supply LLC [Member] | Pennsylvania - State [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2008 and prior
PPL Energy Supply LLC [Member] | Montana - State [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2008 and prior
PPL Electric Utilities Corp [Member]
Unrecognized Tax Benefits (Details) [Roll Forward]
Beginning of period	73		62
Reductions based on tax positions of prior years	(43)
Additions based on tax positions related to the current year	5		22
Reductions based on tax positions related to the current year			(1)
Lapse of applicable statute of limitation	(9)		(10)
End of period	26		73		62
Unrecognized Tax Benefits - Probable Increase (Decrease) Next 12 Months (Details) [Abstract]
Total amount unrecognized tax benefits may increase in next 12 months	11
Total amount unrecognized tax benefits may decrease in next 12 months	25
Total unrecognized tax benefits and related effects that, if recognized, would decrease the effective tax rate	3		8
Open Tax Positions - Accrued Interest (Numeric) [Abstract]
Accrued interest receivable (payable) related to tax positions	1		8
Open Tax Positions - Interest and Penalties (Numeric) [Abstract]
Interest expense (benefit) related to tax positions	$ (4)		$ (5)		$ (8)
Income Tax Examination (Details) [Line Items]
Number of major tax jurisdictions tax returns are filed	2
Tax Legislation (Numeric) [Abstract]
Bonus depreciation expensing provision for qualifying property	50.00%
PPL Electric Utilities Corp [Member] | US - Federal [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	1997 and prior
PPL Electric Utilities Corp [Member] | Pennsylvania - State [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2008 and prior
LG And E And KU Energy LLC [Member]
Income Tax Examination (Details) [Line Items]
Number of major tax jurisdictions tax returns are filed	2
Years no longer subject for recently acquired subsidiary	3
Tax Legislation (Numeric) [Abstract]
Bonus depreciation expensing provision for qualifying property	50.00%
LG And E And KU Energy LLC [Member] | US - Federal [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	10/31/2010 and prior	[2]
Years no longer subject for recently acquired subsidiary	2009 and ten month period ending October 31, 2010
LG And E And KU Energy LLC [Member] | Kentucky - State [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2010 and prior
Louisville Gas And Electric Co [Member]
Income Tax Examination (Details) [Line Items]
Number of major tax jurisdictions tax returns are filed	2
Years no longer subject for recently acquired subsidiary	3
Tax Legislation (Numeric) [Abstract]
Bonus depreciation expensing provision for qualifying property	50.00%
Louisville Gas And Electric Co [Member] | US - Federal [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	10/31/2010 and prior	[2]
Years no longer subject for recently acquired subsidiary	2009 and ten month period ending October 31, 2010
Louisville Gas And Electric Co [Member] | Kentucky - State [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2010 and prior
Kentucky Utilities Co [Member]
Income Tax Examination (Details) [Line Items]
Number of major tax jurisdictions tax returns are filed	2
Years no longer subject for recently acquired subsidiary	3
Tax Legislation (Numeric) [Abstract]
Bonus depreciation expensing provision for qualifying property	50.00%
Kentucky Utilities Co [Member] | US - Federal [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	10/31/2010 and prior	[2]
Years no longer subject for recently acquired subsidiary	2009 and ten month period ending October 31, 2010
Kentucky Utilities Co [Member] | Kentucky - State [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2010 and prior

[1] Represents unrecognized tax benefits derecognized as a result of PPL Energy Supply's distribution of its membership interest in PPL Global to PPL Energy Supply's parent, PPL Energy Funding. See Note 9 for additional information on the distribution.

[2] For LKE, LG&E and KU 2009, as well as the ten month period ending October 31, 2010, remain open under the standard three year statute of limitations; however, the IRS has completed its audit of these periods under the Compliance Assurance Process, effectively closing them to audit adjustments. No issues remain outstanding.