Outstanding Insurance Exposure Outstanding Insurance Exposure - Schedule of Non-Financial Guaranty Exposure (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Schedule of Insured Financial Obligations [Line Items]
Gross Exposure	$ 1,405	$ 1,444
Net exposure	1,108	1,141
Life Insurance Transaction
Schedule of Insured Financial Obligations [Line Items]
Gross Exposure	1,025	1,046
Net exposure	883	898
Aircraft residual value insurance policies
Schedule of Insured Financial Obligations [Line Items]
Gross Exposure	380	398
Net exposure	$ 225	$ 243