Asset Retirement Obligations - PAC - Asset Retirement Obligations By Type (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Asset Retirement Obligations By Type [Line Items]
Regulatory liabilities	$ 6,960	$ 7,221
PAC
Asset Retirement Obligations By Type [Line Items]
Regulatory liabilities	2,650	2,727
PAC \| Cost of removal
Asset Retirement Obligations By Type [Line Items]
Regulatory liabilities	$ 1,187	$ 1,125

The amount for the individual regulatory noncurrent liability as itemized in a table of regulatory noncurrent liabilities as of the end of the period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.24)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Name:	us-gaap_RegulatoryLiabilityNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant