New Accounting Standards - Liability For Future Policy Benefits To Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Jan. 01, 2021	Dec. 31, 2020
Liability for Future Policy Benefit, Activity [Line Items]
Additional insurance liabilities				$ 2,008,399	$ 2,218,116
Total future policy benefits				24,994,257	15,243,536
Unearned and advance premium	$ 271,517	$ 253,140		243,369	61,728
Policy claims and other benefits payable	489,296	507,219		473,524	399,507
Other policyholders' funds	142,686	123,236		98,459	97,968
Total policy liabilities	19,800,073	$ 18,923,637		25,809,609	15,802,739
Life
Liability for Future Policy Benefit, Activity [Line Items]
Total future policy benefits	14,798,356		$ 17,222,992	19,987,227	10,910,418
Health
Liability for Future Policy Benefit, Activity [Line Items]
Total future policy benefits	$ 2,296,260		$ 2,617,575	$ 2,998,631	$ 2,115,002