Income Taxes - Narrative (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
	Jul. 08, 2022	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Aug. 16, 2022
Income Tax Contingency [Line Items]
Unrecognized tax benefits, increase resulting from certain federal tax credits		$ 2
Unrecognized tax benefits period increase (decrease)				$ 31
Unrecognized tax benefits that would impact effective tax rate		24		24
Excess deferred tax amortization due to the Tax Act		(15)	$ (13)	(46)	$ (39)
Income tax expense		105	$ 88	237	271
Excess deferred income taxes				221	$ 255
Operating loss carryforwards, subject to expiration						$ 7,000
Operating loss carryforwards, subject to expiration, net of tax						$ 1,500
Operating loss carryforwards, not subject to expiration		4,900		4,900
Operating loss carryforwards, not subject to expiration, net of tax		$ 1,000		$ 1,000
Pennsylvania
Income Tax Contingency [Line Items]
Excess deferred tax amortization due to the Tax Act	$ 225
Regulatory liabilities	229
Income tax expense	$ 4