Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Foreign currency translation adjustments:
Change in unrealized foreign currency translation gains (losses) before income taxes	$ (3,817)	$ 7,005	$ (13,272)	$ 8,026
Change in unrealized foreign currency translation gains (losses), net of income taxes	(3,817)	7,005	(13,272)	8,026
Unrealized gain (losses) on available-for-sale securities:
Change in unrealized holding gains (losses) arising during period before income taxes	(6,756)	(23,068)	(21,602)	15,364
Income tax expense (benefit) on unrealized holding gains (losses) arising during period	(1,395)	(5,237)	(4,716)	2,970
Change in unrealized holding gains (losses) on available-for-sale securities arising during period, net of income taxes	(5,361)	(17,831)	(16,886)	12,394
Reclassification from accumulated OCI to net income for (gains) losses realized on available-for-sale securities	(565)	(331)	(572)	2,815
Income tax (expense) benefit on (gains) losses reclassified from accumulated OCI to net income	(119)	(70)	(120)	591
Reclassification from accumulated OCI to net income for (gains) losses realized on available-for-sale securities, net of income taxes	(446)	(261)	(452)	2,224
Change in unrealized gains (losses) on available-for-sale securities, net of income taxes and reclassification adjustment	(5,807)	(18,092)	(17,338)	14,618
Effect of change in discount rate assumptions on the LFPB:
Change in effect in discount rate assumptions on the LFPB before income taxes	137,798	85,310	305,884	(95,971)
Income tax (expense) benefit on the effect of change in discount rate assumptions on the LFPB from accumulated OCI to net income	29,211	17,958	65,357	(20,941)
Change in effect in discount rate assumptions on the LFPB, net of income taxes	$ 108,587	$ 67,352	$ 240,527	$ (75,030)