Costs billed to the company from a services affiliate. These costs include direct costs that are specifically related to the company or, for general costs that cannot be directly attributed, they are charged based on predetermined allocation factors and costs incurred where the service company has made a "convenience" payment on behalf of the company.

No definition available.

Related Party Transactions (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		12 Months Ended
	May 31, 2018	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Feb. 28, 2018
PPL Electric Utilities Corp [Member] \| PPL Services [Member]
Support Costs (Details) [Abstract]
Support cost allocations from subsidiary of parent to registrant		$ 16	$ 51
PPL Electric Utilities Corp [Member] \| PPL EU Services [Member]
Support Costs (Details) [Abstract]
Support cost allocations from subsidiary of parent to registrant		35	18
PPL Electric Utilities Corp [Member] \| PPL Energy Funding [Member]
Intercompany Borrowings (Numeric) [Abstract]
Intercompany note with affiliate maximum borrowing capacity		400
Notes receivable from affiliate		0		$ 0
LG And E And KU Energy LLC [Member]
Intercompany Borrowings (Numeric) [Abstract]
Notes payable to affiliates		237		225
Long-term debt to affiliate		400		400
Interest Expense with Affiliate		5	4
LG And E And KU Energy LLC [Member] \| PPL Services [Member]
Support Costs (Details) [Abstract]
Support cost allocations from subsidiary of parent to registrant		7	6
LG And E And KU Energy LLC [Member] \| PPL Energy Funding [Member]
Intercompany Borrowings (Numeric) [Abstract]
Intercompany note with affiliate maximum borrowing capacity		300
Notes payable to affiliates		$ 237		$ 225
Intercompany borrowings demand note rate on outstanding borrowing		3.17%		2.87%
Intercompany Note Affiliate Maximum Borrowing Capacity Increase					$ 25
LG And E And KU Energy LLC [Member] \| PPL Affiliate [Member]
Intercompany Borrowings (Numeric) [Abstract]
Debt instrument term (in years)		10 years
Long-term debt to affiliate		$ 400
Interest rate on ten-year note		3.50%
Interest Expense with Affiliate		$ 4	4
LG And E And KU Energy LLC [Member] \| Note Payable [Member] \| Affiliated Entity [Member] \| Subsequent Event [Member]
Intercompany Borrowings (Numeric) [Abstract]
Stated interest rate	4.00%
Maturity date	May 31, 2028
Notes Payable, Noncurrent	$ 250
Louisville Gas And Electric Co [Member] \| LKS [Member]
Intercompany Billings by LKS (Details) [Abstract]
Intercompany billings between affiliates		38	44
Kentucky Utilities Co [Member] \| LKS [Member]
Intercompany Billings by LKS (Details) [Abstract]
Intercompany billings between affiliates		$ 42	$ 44