Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018	Sep. 30, 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	$ 670		$ 621
Restricted Cash, Current	3		3
Restricted Cash, Noncurrent	17		19
Cash, Cash Equivalents and Restricted Cash	690		643	$ 864	$ 511
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	97	$ 81
Lease Liability - Current	25	23
Lease Liability - Noncurrent	80	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	27		267
Restricted Cash, Current	2		2
Restricted Cash, Noncurrent	0		0
Cash, Cash Equivalents and Restricted Cash	29		269	416	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	30		24	29	30
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	47	56
Lease Liability - Current	16	18
Lease Liability - Noncurrent	39	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	12		10	11	15
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	19	23
Lease Liability - Current	6	9
Lease Liability - Noncurrent	16	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	18		$ 14	$ 18	$ 15
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	27	31
Lease Liability - Current	9	9
Lease Liability - Noncurrent	$ 22	$ 26