Significant Accounting Policies - Deferred Acquisition Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred acquisition costs, beginning of the period	$ 1,747	$ 1,502
Capitalizations	516	544
Amortization expense	(346)	(299)
Deferred acquisition costs, end of the period	$ 1,917	$ 1,747