Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Numerator for diluted and basic earnings per share:
Net income	$ 158,373	$ 152,528
Denominator — share:
Basic weighted-average shares (in shares)	23,723	24,378
Effect of dilutive securities (in shares)	235	449
Diluted weighted-average shares (in shares)	23,958	24,827
Earnings per share:
Basic (in dollars per share)	$ 6.68	$ 6.26
Diluted (in dollars per share)	$ 6.61	$ 6.14