Other Financial Information - Schedule of Other Noncurrent Assets (Detail) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Other Financial Information [Abstract]
Prepaid gas transmission contract	$ 285	$ 278
Gas supply prepayment	220	225
Value added tax credits	211	213
Deferred mining costs, net	196	184
Goodwill	143	142
Prepaid pension benefit	131	128
IRA Section 45X credit	85	71
Noncurrent restricted cash	68	53
Noncurrent prepaid tax asset	67	66
Intangibles, net	35	36
Other	101	101
Other assets, noncurrent, total	$ 1,542	$ 1,497