Policyholders' Liabilities (Additional Insurance Reserves) (Details) - Variable/Universal Life - Policyholder Contract Deposit - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance, beginning of period	$ 3,067,335	$ 2,398,788
Unearned revenue	200,262	195,794
Amortization expense	32,752	32,330
Other adjustments	(90)
Balance, end of period	3,234,755	2,562,252
Reinsurance recoverables	1,583,054	1,401,741
Unearned revenue reserve net of reinsurance recoverables	$ 1,651,701	$ 1,160,511