Nuclear Decommissioning - Rollforward of Nuclear Decommissioning ARO (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accretion expense	$ 44	$ 255

Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)(3)
-URI https://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

Name:	us-gaap_AssetRetirementObligationAccretionExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration