Policyholders' Liabilities (Additional Insurance Reserves) (Details) - Variable/Universal Life - Policyholder Contract Deposit - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Policyholder Account Balance, Unearned Revenue Reserve	$ 3,067,336	$ 2,398,788
Policyholder Account Balance, Unearned Revenue Reserve, Issuance	405,732	393,675
Policyholder Account Balance, Unearned Revenue Reserve, Amortization Expense	(70,981)	(63,472)
Other adjustments	(93)	66
Policyholder Account Balance, Unearned Revenue Reserve	3,401,994	2,729,057
Policyholder Account Balance, Unearned Revenue Reserve, Reinsurance	1,621,229	1,450,592
Unearned revenue reserve net of reinsurance recoverables	$ 1,780,765	$ 1,278,465