Summary of Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Depreciation [Line Items]
Reduction in depreciation expense in 2013 as a result of lower weighted-average rates	$ 19
Unaffiliated Third Party Entity [Member]
Accounts Receivable (Numeric) [Abstract]
Purchases of accounts receivable	259	238
PPL Electric Utilities Corp [Member] | Unaffiliated Third Party Entity [Member]
Accounts Receivable (Numeric) [Abstract]
Purchases of accounts receivable	259	238
PPL Electric Utilities Corp [Member] | Affiliated Entity [Member]
Accounts Receivable (Numeric) [Abstract]
Purchases of accounts receivable	77	82
LG And E And KU Energy LLC [Member]
Depreciation [Line Items]
Reduction in depreciation expense in 2013 as a result of lower weighted-average rates	19
Louisville Gas And Electric Co [Member]
Depreciation [Line Items]
Reduction in depreciation expense in 2013 as a result of lower weighted-average rates	9
Kentucky Utilities Co [Member]
Depreciation [Line Items]
Reduction in depreciation expense in 2013 as a result of lower weighted-average rates	$ 10