Contracts Accounted for as Insurance - Selected Information for Policies Paid In Installments (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Financial Guarantee Insurance Premiums [Line Items]
Premiums receivable, net of commissions payable	$ 1,346	$ 1,298	$ 1,335	$ 1,372
Financial Guarantee Policies Paid in Installments
Financial Guarantee Insurance Premiums [Line Items]
Premiums receivable, net of commissions payable	1,345	1,297
Deferred premium revenue	$ 1,699	$ 1,663
Weighted-average risk-free rate used to discount premiums	1.80%	1.80%
Weighted-average period of premiums receivable (in years)	12 years 7 months 6 days	12 years 10 months 24 days