Regulatory Matters - Schedule of Annualized Incremental Revenues (Details) - USD ($) $ in Millions						9 Months Ended
	Sep. 16, 2026	Jul. 01, 2026	Jun. 30, 2026	Apr. 01, 2026	Jan. 01, 2026	Sep. 30, 2026
Public Utilities, General Disclosures
Total infrastructure surcharge authorizations						$ 105
Missouri
Public Utilities, General Disclosures
Infrastructure surcharge, annualized incremental revenues, authorized amount	$ 14
Missouri \| Public Utility, Authorization, Effective Date, August 15, 2026
Public Utilities, General Disclosures
Total infrastructure surcharge authorizations						18
Missouri \| Public Utility, Authorization, Effective Date, March 1, 2026
Public Utilities, General Disclosures
Total infrastructure surcharge authorizations						13
Pennsylvania
Public Utilities, General Disclosures
Total infrastructure surcharge authorizations						27
Infrastructure surcharge, annualized incremental revenues, authorized amount		$ 9		$ 7	$ 11
New Jersey
Public Utilities, General Disclosures
Total infrastructure surcharge authorizations						25
Indiana
Public Utilities, General Disclosures
Total infrastructure surcharge authorizations						15
West Virginia
Public Utilities, General Disclosures
Total infrastructure surcharge authorizations						2
Infrastructure surcharge, annualized incremental revenues, authorized amount			$ 5
Illinois
Public Utilities, General Disclosures
Total infrastructure surcharge authorizations						$ 5