v3.26.1
ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
Beginning balance     $ 941,170  
Change in accumulated other comprehensive income (loss) before reclassifications $ (4,621) $ 6,736 (20,495) $ 27,679
Reclassification adjustments from accumulated other comprehensive income (loss) 338 791 539 1,387
Ending balance 977,337 845,668 977,337 845,668
Total        
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
Beginning balance (20,736) (33,242) (5,063) (54,781)
Ending balance (25,019) (25,715) (25,019) (25,715)
Net unrealized gain (loss) on investments        
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
Beginning balance (39,917) (51,702) (25,268) (72,241)
Change in accumulated other comprehensive income (loss) before reclassifications (4,089) 6,174 (18,939) 26,117
Reclassification adjustments from accumulated other comprehensive income (loss) 338 791 539 1,387
Ending balance (43,668) (44,737) (43,668) (44,737)
Net benefit plan assets and obligations        
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
Beginning balance 17,987 17,088 18,559 17,660
Change in accumulated other comprehensive income (loss) before reclassifications (572) (572) (1,144) (1,144)
Reclassification adjustments from accumulated other comprehensive income (loss) 0 0 0 0
Ending balance 17,415 16,516 17,415 16,516
Foreign currency translation adjustment        
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
Beginning balance 1,194 1,372 1,646 (200)
Change in accumulated other comprehensive income (loss) before reclassifications 40 1,134 (412) 2,706
Reclassification adjustments from accumulated other comprehensive income (loss) 0 0 0 0
Ending balance $ 1,234 $ 2,506 $ 1,234 $ 2,506