Income taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Company retirement benefit plans	$ 2	$ 38
Revaluation of derivative financial instruments to fair value	4	2
Tax losses, credits and interest deduction carryforwards	1,149	1,052
Share-based compensation	39	41
Accrued expenses	454	420
Lease liabilities	286	292
Total deferred tax assets	1,934	1,845
Less: valuation allowances	(1,059)	(914)	$ (737)	$ (578)
Total deferred tax assets after valuation allowances	875	931
Deferred tax liabilities:
Investment in subsidiaries	146	155
Depreciation, depletion and amortization	3,419	3,109
Leased right-of-use assets	278	274
Rolled-over capital gains	21	21
Other	15	12
Total deferred tax liabilities	3,879	3,571
Total net deferred tax liabilities	$ 3,004	$ 2,640