Insurance Contracts - Premium Earned (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Insurance [Line Items]
Premiums Earned, Net	$ 11	$ 11	$ 25	$ 21
Direct Premiums Written	(3)	(1)	(5)	10
Direct Premiums Earned	14	14	31	27
Assumed Reinsurance Premiums Written	0	0	0	0
Assumed Reinsurance Premiums Earned	0	0	0	1
Ceded Premiums Written	9	0	16	(1)
Ceded Reinsurance Premiums Earned	3	3	6	6
Premiums Written, Net	(13)	0	(21)	11
Premiums Receivable, Net	$ 345		$ 345		$ 370
Estimated Future Premium Payments Weighted Average Discounted Rate	2.20%		2.20%		2.20%
Weighted average period of future premiums			8 years 3 months 18 days		8 years 3 months 18 days
Reportable Geographical Components [Member] | United States [Member]
Insurance [Line Items]
Premiums Earned, Net	$ 7	8	$ 14	15
Reportable Geographical Components [Member] | United Kingdom [Member]
Insurance [Line Items]
Premiums Earned, Net	4	4	7	8
Reportable Geographical Components [Member] | Other International [Member]
Insurance [Line Items]
Premiums Earned, Net	$ 1	$ (1)	$ 4	$ (1)