Deferred Policy Acquisition Costs - ASU 2018-12 Transition Deferred Acquisition Costs Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
ASU 2018-12
Deferred policy acquisition costs	$ 1,048	$ 1,013	$ 984	$ 916
Accounting Standards Update 2018-12
ASU 2018-12
Deferred policy acquisition costs		1,013			$ 296
Effect of Modified Retrospective Application Accounting Standards Update 2018-12 | Accounting Standards Update 2018-12
ASU 2018-12
Deferred policy acquisition costs		$ (1)			$ 33