Policyholders' Liabilities (Future Policy Benefits) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Liability for Future Policy Benefit, before Reinsurance [Abstract]
Life insurance – domestic	$ 643	$ 71
Individual and group annuities and supplementary contracts	431,421	1,223,557
Other contract liabilities	4,072,943	17,337,263
Total future policy benefits	$ 4,505,007	$ 18,560,891