Outstanding Exposure Outstanding Exposure - Schedule of Non-Financial Guaranty Exposure (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Life Insurance Transaction [Member]
Schedule of Insured Financial Obligations [Line Items]
Gross Exposure	$ 1,014	$ 880
Net Exposure	872	763
Aircraft residual value insurance policies [Member]
Schedule of Insured Financial Obligations [Line Items]
Gross Exposure	376	340
Net Exposure	$ 243	$ 218