Derivative Instruments and Hedging Activities - Intro (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Master Netting Arrangements (Numeric) [Line Items]
Cash collateral obligation under master netting arrangements	$ 9	$ 0
Louisville Gas And Electric Co [Member]
Master Netting Arrangements (Numeric) [Line Items]
Cash collateral obligation under master netting arrangements	0	0
Kentucky Utilities Co [Member]
Master Netting Arrangements (Numeric) [Line Items]
Cash collateral obligation under master netting arrangements	$ 0	$ 0

Amount of obligation to return cash collateral under master netting arrangements that have not been offset against derivative assets.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
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-Publisher FASB
-Name Accounting Standards Codification
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant