Expected Loss to be Paid (Recovered) - Net Expected Loss to be Paid (Recovered) and Net Economic Loss Development (Benefit) by Accounting Model (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of Expected Losses to be Paid [Line Items]
Net Expected Loss to be Paid (Recovered)	$ 411	$ 529	$ 737	$ 1,183
Net Economic Loss Development (Benefit)	(287)	145	(1)
Insurance Contracts
Schedule of Expected Losses to be Paid [Line Items]
Net Expected Loss to be Paid (Recovered)	364	471
Net Economic Loss Development (Benefit)	(281)	142	14
Financial Guarantee Variable Interest Entities
Schedule of Expected Losses to be Paid [Line Items]
Net Expected Loss to be Paid (Recovered)	42	59
Net Economic Loss Development (Benefit)	(20)	1	(29)
Financial Guarantee Accounted for as Credit Derivatives
Schedule of Expected Losses to be Paid [Line Items]
Net Expected Loss to be Paid (Recovered)	5	(1)
Net Economic Loss Development (Benefit)	$ 14	$ 2	$ 14