Fair Value of Financial Instruments - Retail Customer Credit Risk (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Derivative Fair Value Meaurements and Concentration of Credit Risk
Provision for credit losses (income recognized) due to loss mitigation efforts	$ 11	$ 698	$ 108
Winter Storm Uri
Derivative Fair Value Meaurements and Concentration of Credit Risk
Provision for credit losses (income recognized) due to loss mitigation efforts	$ (126)	$ 596

Amount of expense (reversal of expense) for expected credit loss on accounts receivable.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(5))
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

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