Future Policy Benefits - Schedule of Revenue and Interest Expense in Respect of Future Policy Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Disclosure In Tabular Form Of Revenue And Interest Expense In Respect Of Future Policy Benefits [Line Items]
Gross premiums	$ 3,141	$ 3,167	$ 3,401
Interest accretion	3,065	3,054	3,060
Long-term care insurance
Disclosure In Tabular Form Of Revenue And Interest Expense In Respect Of Future Policy Benefits [Line Items]
Gross premiums	2,544	2,520	2,713
Interest accretion	2,406	2,361	2,333
Life insurance
Disclosure In Tabular Form Of Revenue And Interest Expense In Respect Of Future Policy Benefits [Line Items]
Gross premiums	597	647	688
Interest accretion	42	54	64
Fixed annuities
Disclosure In Tabular Form Of Revenue And Interest Expense In Respect Of Future Policy Benefits [Line Items]
Gross premiums	0	0	0
Interest accretion	$ 617	$ 639	$ 663