Insurance Contracts - Summarized Future Gross Undiscounted Premiums Expected to be Collected, and Future Expected Premiums Earned, Net of Reinsurance (Details) $ in Millions	Jun. 30, 2022 USD ($)
Future premiums expected to be collected, September 30, 2021	$ 8
Future premiums expected to be collected, December 31, 2021	6
Future premiums expected to be collected, December 31, 2022	29
Future premiums expected to be collected, December 31, 2023	28
Future premiums expected to be collected, December 31, 2024	27
Future premiums expected to be collected, December 31, 2025	26
Future premiums expected to be collected, December 31, 2030	111
Future premiums expected to be collected, December 31, 2035	74
Future premiums expected to be collected, December 31, 2040	34
Future premiums expected to be collected, December 31, 2045	16
Future premiums expected to be collected, December 31, 2050	5
Future premiums expected to be collected, December 31, 2055	0
Future premiums expected to be collected, Total	363
Future expected premiums to be earned, net of reinsurance, September 30, 2021	6
Future expected premiums to be earned, net of reinsurance, December 31, 2021	6
Future expected premiums to be earned, net of reinsurance, December 31, 2022	23
Future expected premiums to be earned, net of reinsurance, December 31, 2023	22
Future expected premiums to be earned, net of reinsurance, December 31, 2024	21
Future expected premiums to be earned, net of reinsurance, December 31, 2025	21
Future expected premiums to be earned, net of reinsurance, December 31, 2030	85
Future expected premiums to be earned, net of reinsurance, December 31, 2035	53
Future expected premiums to be earned, net of reinsurance, December 31, 2040	21
Future expected premiums to be earned, net of reinsurance, December 31, 2045	9
Future expected premiums to be earned, net of reinsurance, December 31, 2050	3
Future expected premiums to be earned, net of reinsurance, December 31, 2055	0
Future expected premiums to be earned, net of reinsurance, Total	$ 270