Deferred Acquisition Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Movement Analysis of Deferred Policy Acquisition Costs
Balance at beginning of year	$ 4,914,728	$ 4,595,444	$ 4,341,941
Deferred during period:
Commissions	710,659	678,517	600,577
Other expenses	249,924	227,730	222,408
Total deferred	960,583	906,247	822,985
Value of business acquired	0	16,500	0
Foreign exchange adjustment	0	0	4,755
Adjustment attributable to unrealized investment losses	9,707	1,628	1,533
Total additions	970,290	924,375	829,273
Amortized during period	(624,407)	(603,838)	(575,770)
Foreign exchange adjustment	(10,704)	(1,253)	0
Total deductions	(635,111)	(605,091)	(575,770)
Balance at end of year	$ 5,249,907	$ 4,914,728	$ 4,595,444