Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Reconciliation of Cash, Cash Equivalents and Restricted Cash from the Balance Sheet to Cash Flow Statement [Line Items]
Cash and cash equivalents	$ 518		$ 621
Restricted Cash, Current	3		3
Restricted Cash, Noncurrent	19		19
Cash, Cash Equivalents and Restricted Cash	540		643	$ 653	$ 511
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	76	$ 81
Lease Liability - Current	21	23
Lease Liability - Noncurrent	64	67
PPL Electric Utilities Corp [Member]
Reconciliation of Cash, Cash Equivalents and Restricted Cash from the Balance Sheet to Cash Flow Statement [Line Items]
Cash and cash equivalents	23		267
Restricted Cash, Current	2		2
Restricted Cash, Noncurrent	0		0
Cash, Cash Equivalents and Restricted Cash	25		269	22	51
LG And E And KU Energy LLC [Member]
Reconciliation of Cash, Cash Equivalents and Restricted Cash from the Balance Sheet to Cash Flow Statement [Line Items]
Cash and cash equivalents	22		24	27	30
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	51	56
Lease Liability - Current	16	18
Lease Liability - Noncurrent	43	46
Louisville Gas And Electric Co [Member]
Reconciliation of Cash, Cash Equivalents and Restricted Cash from the Balance Sheet to Cash Flow Statement [Line Items]
Cash and cash equivalents	9		10	14	15
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	20	23
Lease Liability - Current	7	9
Lease Liability - Noncurrent	18	18
Kentucky Utilities Co [Member]
Reconciliation of Cash, Cash Equivalents and Restricted Cash from the Balance Sheet to Cash Flow Statement [Line Items]
Cash and cash equivalents	13		$ 14	$ 11	$ 15
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	29	31
Lease Liability - Current	9	9
Lease Liability - Noncurrent	$ 24	$ 26