Fair Value Measurements - Assets and Liabilities Measured on Recurring Basis Table (Details) - Recurring Fair Value Measurements [Member] - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Assets
Cash and cash equivalents		$ 416	$ 836
Restricted cash and cash equivalents	[1]	29	33
Price risk management assets:
Foreign currency contracts assets	[2]	110	209
Cross-currency swaps assets	[2]	153	86
Total price risk management assets	[2]	263	295
Auction rate securities		0	2	[3]
Total assets		708	1,166
Price risk management liabilities:
Interest rate swaps liabilities	[2]	54	71
Foreign currency contracts liabilities	[2]	14	1
Total price risk management liabilities	[2]	68	72
Level 1 [Member]
Assets
Cash and cash equivalents		416	836
Restricted cash and cash equivalents	[1]	29	33
Price risk management assets:
Foreign currency contracts assets		0	0
Cross-currency swaps assets		0	0
Total price risk management assets		0	0
Auction rate securities		0	0
Total assets		445	869
Price risk management liabilities:
Interest rate swaps liabilities		0	0
Foreign currency contracts liabilities		0	0
Total price risk management liabilities		0	0
Level 2 [Member]
Assets
Cash and cash equivalents		0	0
Restricted cash and cash equivalents		0	0
Price risk management assets:
Foreign currency contracts assets	[2]	110	209
Cross-currency swaps assets	[2]	153	86
Total price risk management assets	[2]	263	295
Auction rate securities		0	0
Total assets		263	295
Price risk management liabilities:
Interest rate swaps liabilities	[2]	54	71
Foreign currency contracts liabilities	[2]	14	1
Total price risk management liabilities	[2]	68	72
Level 3 [Member]
Assets
Cash and cash equivalents		0	0
Restricted cash and cash equivalents		0	0
Price risk management assets:
Foreign currency contracts assets		0	0
Cross-currency swaps assets		0	0
Total price risk management assets		0	0
Auction rate securities		0	2	[3]
Total assets		0	2
Price risk management liabilities:
Interest rate swaps liabilities		0	0
Foreign currency contracts liabilities		0	0
Total price risk management liabilities		0	0
PPL Electric Utilities Corp [Member]
Assets
Cash and cash equivalents		36	47
Restricted cash and cash equivalents	[1]	2	2
Price risk management assets:
Total assets		38	49
PPL Electric Utilities Corp [Member] | Level 1 [Member]
Assets
Cash and cash equivalents		36	47
Restricted cash and cash equivalents	[1]	2	2
Price risk management assets:
Total assets		38	49
PPL Electric Utilities Corp [Member] | Level 2 [Member]
Assets
Cash and cash equivalents		0	0
Restricted cash and cash equivalents		0	0
Price risk management assets:
Total assets		0	0
PPL Electric Utilities Corp [Member] | Level 3 [Member]
Assets
Cash and cash equivalents		0	0
Restricted cash and cash equivalents		0	0
Price risk management assets:
Total assets		0	0
LG And E And KU Energy LLC [Member]
Assets
Cash and cash equivalents		11	30
Cash collateral posted to counterparties	[4]	8	9
Price risk management assets:
Total assets		19	39
Price risk management liabilities:
Interest rate swaps liabilities		54	47
Total price risk management liabilities		54	47
LG And E And KU Energy LLC [Member] | Level 1 [Member]
Assets
Cash and cash equivalents		11	30
Cash collateral posted to counterparties	[4]	8	9
Price risk management assets:
Total assets		19	39
Price risk management liabilities:
Interest rate swaps liabilities		0	0
Total price risk management liabilities		0	0
LG And E And KU Energy LLC [Member] | Level 2 [Member]
Assets
Cash and cash equivalents		0	0
Cash collateral posted to counterparties		0	0
Price risk management assets:
Total assets		0	0
Price risk management liabilities:
Interest rate swaps liabilities		54	47
Total price risk management liabilities		54	47
LG And E And KU Energy LLC [Member] | Level 3 [Member]
Assets
Cash and cash equivalents		0	0
Cash collateral posted to counterparties		0	0
Price risk management assets:
Total assets		0	0
Price risk management liabilities:
Interest rate swaps liabilities		0	0
Total price risk management liabilities		0	0
Louisville Gas And Electric Co [Member]
Assets
Cash and cash equivalents		4	19
Cash collateral posted to counterparties	[4]	8	9
Price risk management assets:
Total assets		12	28
Price risk management liabilities:
Interest rate swaps liabilities		54	47
Total price risk management liabilities		54	47
Louisville Gas And Electric Co [Member] | Level 1 [Member]
Assets
Cash and cash equivalents		4	19
Cash collateral posted to counterparties	[4]	8	9
Price risk management assets:
Total assets		12	28
Price risk management liabilities:
Interest rate swaps liabilities		0	0
Total price risk management liabilities		0	0
Louisville Gas And Electric Co [Member] | Level 2 [Member]
Assets
Cash and cash equivalents		0	0
Cash collateral posted to counterparties		0	0
Price risk management assets:
Total assets		0	0
Price risk management liabilities:
Interest rate swaps liabilities		54	47
Total price risk management liabilities		54	47
Louisville Gas And Electric Co [Member] | Level 3 [Member]
Assets
Cash and cash equivalents		0	0
Cash collateral posted to counterparties		0	0
Price risk management assets:
Total assets		0	0
Price risk management liabilities:
Interest rate swaps liabilities		0	0
Total price risk management liabilities		0	0
Kentucky Utilities Co [Member]
Assets
Cash and cash equivalents		7	11
Price risk management assets:
Total assets		7	11
Kentucky Utilities Co [Member] | Level 1 [Member]
Assets
Cash and cash equivalents		7	11
Price risk management assets:
Total assets		7	11
Kentucky Utilities Co [Member] | Level 2 [Member]
Assets
Cash and cash equivalents		0	0
Price risk management assets:
Total assets		0	0
Kentucky Utilities Co [Member] | Level 3 [Member]
Assets
Cash and cash equivalents		0	0
Price risk management assets:
Total assets		$ 0	$ 0

[1] Current portion is included in "Other current assets" and long-term portion is included in "Other noncurrent assets" on the Balance Sheets.

[2] Current portion is included in "Price risk management assets" and "Other current liabilities" and noncurrent portion is included in "Price risk management assets" and "Other deferred credits and noncurrent liabilities" on the Balance Sheets.

[3] Included in "Other noncurrent assets" on the Balance Sheets.

[4] Included in "Other noncurrent assets" on the Balance Sheets. Represents cash collateral posted to offset the exposure with counterparties related to certain interest rate swaps under master netting arrangements that are not offset.