Consolidated Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025
Statement of Cash Flows [Abstract]
Advances and contributions in aid of construction, refunds	$ 24	$ 25

The cash outflow from repayment of borrowings to finance the cost of construction.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 15
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-15

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