Outstanding Exposure - Schedule of Non-Financial Guaranty Exposure (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Schedule of Insured Financial Obligations [Line Items]
Gross Exposure	$ 1,577	$ 1,484
Net Exposure	1,038	928
Life Insurance Transaction
Schedule of Insured Financial Obligations [Line Items]
Gross Exposure	1,222	1,121
Net Exposure	838	720
Life Insurance Transaction | Maximum
Schedule of Insured Financial Obligations [Line Items]
Net Exposure	1,100
Aircraft residual value insurance policies
Schedule of Insured Financial Obligations [Line Items]
Gross Exposure	355	363
Net Exposure	$ 200	$ 208