Other Financial Information - Schedule of Other Noncurrent Assets (Detail) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Other Financial Information [Abstract]
Prepaid gas transmission contract	$ 296	$ 278
Gas supply prepayment	219	225
Value added tax credits	208	213
Deferred mining costs, net	215	184
Goodwill	144	142
Prepaid pension benefit	138	128
IRA Section 45X credit	101	71
Noncurrent restricted cash	68	53
Intangibles, net	34	36
Noncurrent prepaid tax asset	0	66
Other	105	101
Other assets, noncurrent, total	$ 1,528	$ 1,497