v3.26.1
SHAREHOLDERS' EQUITY - Schedule of Changes in Accumulated Other Comprehensive Income (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Jun. 30, 2026
Jun. 30, 2026
Rollforward of accumulated other comprehensive income (loss), net of tax    
Beginning balance $ 2,629,857 $ 2,829,338
Activity during the period    
Ending balance 2,670,409 2,670,409
Accumulated Other Comprehensive Income (Loss)    
Rollforward of accumulated other comprehensive income (loss), net of tax    
Beginning balance 43,496 44,964
Activity during the period    
Other comprehensive loss before reclassifications (13,263) (15,369)
Amounts reclassified from accumulated other comprehensive income (loss)   638
Net current-period other comprehensive income (loss) (13,263) (14,731)
Ending balance 30,233 30,233
Defined Benefit Pension Plan    
Rollforward of accumulated other comprehensive income (loss), net of tax    
Beginning balance 5,404 4,470
Activity during the period    
Other comprehensive loss before reclassifications 0 0
Amounts reclassified from accumulated other comprehensive income (loss)   934
Net current-period other comprehensive income (loss) 0 934
Ending balance 5,404 5,404
Unrealized Gain on Available-for-Sale Security    
Rollforward of accumulated other comprehensive income (loss), net of tax    
Beginning balance 0 296
Activity during the period    
Other comprehensive loss before reclassifications 0 0
Amounts reclassified from accumulated other comprehensive income (loss)   (296)
Net current-period other comprehensive income (loss) 0 (296)
Ending balance 0 0
Foreign Currency Translation Adjustment    
Rollforward of accumulated other comprehensive income (loss), net of tax    
Beginning balance 38,092 40,198
Activity during the period    
Other comprehensive loss before reclassifications (13,263) (15,369)
Amounts reclassified from accumulated other comprehensive income (loss)   0
Net current-period other comprehensive income (loss) (13,263) (15,369)
Ending balance $ 24,829 $ 24,829