Income Taxes - Components of Deferred Tax Assets & Liabilities (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Deferred Tax Liabilities
Property, plant and equipment and investments	$ (1,742)	$ (1,712)
Other	(99)	(38)
Total Deferred Tax Liabilities	(1,841)	(1,750)
Deferred Tax Assets
Net operating loss carryforwards	4,226	4,323
Tax credit carryforwards	98	89
Property, plant and equipment and investments	233	258
Accrued compensation, deferred credits and other liabilities	85	71
Asset retirement obligations	279	258
Other	293	277
Total Deferred Tax Assets	5,214	5,276
Valuation allowances	(3,658)	(3,838)
Total deferred tax assets, net of valuation allowances	1,556	1,438
Net Deferred Tax Assets (Liabilities)	(285)	(312)
Valuation allowance increase (decrease) amount	(180)	1,553	$ (657)
Deferred Tax Liabilities, Net [Abstract]
Deferred income taxes (long-term asset)	133	71
Deferred income taxes (long-term liability)	(418)	(383)
Net Deferred Tax Assets (Liabilities)	$ (285)	$ (312)