Taxation (Reconciliation Of The Difference Between The Provision for Income Taxes and the Expected Tax Provision at Swiss Statutory Income Tax Rate) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Expected tax provision at Swiss statutory tax rate	$ 2,251	$ 1,872	$ 1,274
Taxes on earnings subject to rate other than Swiss statutory rate	(510)	(389)	(243)
Bermuda tax law enactment	(55)	(1,135)	0
Net withholding taxes	145	15	75
Other	(16)	148	133
Provision for income taxes	$ 1,815	$ 511	$ 1,239