Consolidated Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Statement of Cash Flows [Abstract]
Income taxes paid on proceeds from issuance of employee stock plans and direct stock purchase plan	$ 12	$ 15
Advances and contributions for construction, refunds	$ 3	$ 6

Amount of cash outflow to satisfy grantee's tax withholding obligation for award under share-based payment arrangement.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585

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