Policyholders' Liabilities (Additional Insurance Reserves) (Details) - Variable / Universal Life - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Liability for Future Policy Benefit, Expected Future Policy Benefit [Roll Forward]
Balance, beginning of period	$ 3,741,426	$ 3,067,336	$ 2,398,788
Unearned revenue	859,231	827,960	799,185
Amortization expense	(185,468)	(153,779)	(129,525)
Other adjustments	(2)	(91)	(1,112)
Balance, end of period	$ 4,415,187	$ 3,741,426	$ 3,067,336