Insurance Subsidiaries - Surplus Notes (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Schedule of Surplus Notes [Line Items]
Surplus Notes	$ 123
Surplus Notes Issued 1994
Schedule of Surplus Notes [Line Items]
Surplus Notes	40	$ 60
Surplus Notes Issued 2000
Schedule of Surplus Notes [Line Items]
Surplus Notes	26	39
Surplus Notes Issued 2017
Schedule of Surplus Notes [Line Items]
Surplus Notes	61	61
Surplus Notes Issued 2018
Schedule of Surplus Notes [Line Items]
Surplus Notes	62	62
Surplus Notes Issued 2019
Schedule of Surplus Notes [Line Items]
Surplus Notes	$ 63	$ 0