CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Sep. 30, 2022		56,425
Beginning balance at Sep. 30, 2022	$ 692,231	$ 564	$ 345,330	$ 402,006	$ (55,669)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation	9,539		9,539
Transfer of equity consideration for acquisition (in shares)		10
Transfer of equity consideration for acquisition	99	$ 0	99
Release of restricted stock, net of shares withheld for taxes (in shares)		373
Release of restricted stock, net of shares withheld for taxes	5	$ 5
Taxes paid related to net share settlement of equity awards (in shares)		(1)
Taxes paid related to net share settlement of equity awards	(1,148)		(1,148)
Foreign currency translation gain (loss)	23,567			0	23,567
Purchase and retirement of treasury stock (in shares)		(1,967)
Purchase and retirement of treasury stock	(16,988)	$ (20)	(7,639)	(9,329)
Net income	38,463			38,463
Ending balance (in shares) at Sep. 30, 2023		54,840
Ending balance at Sep. 30, 2023	745,768	$ 549	346,181	431,140	(32,102)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation	10,406		10,406
Release of restricted stock, net of shares withheld for taxes (in shares)		855
Release of restricted stock, net of shares withheld for taxes	49	$ 9	40
Settlement of conversion premium and issuance of shares to redeem convertible notes (in shares)		77
Settlement of conversion premium and issuance of shares to redeem convertible notes	0	$ 1	(1)
Taxes paid related to net share settlement of equity awards (in shares)		0
Taxes paid related to net share settlement of equity awards	(3,294)		(3,294)
Foreign currency translation gain (loss)	(19,445)				(19,445)
Purchase and retirement of treasury stock (in shares)		(1,219)
Purchase and retirement of treasury stock	(12,008)	$ (13)	(4,966)	(7,029)
Net income	83,095			83,095
Ending balance (in shares) at Sep. 30, 2024		54,553
Ending balance at Sep. 30, 2024	804,571	$ 546	348,366	507,206	(51,547)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation	12,465		12,465
Release of restricted stock, net of shares withheld for taxes (in shares)		794
Release of restricted stock, net of shares withheld for taxes	0	$ 8	(8)
Settlement of conversion premium and issuance of shares to redeem convertible notes (in shares)		6,098
Settlement of conversion premium and issuance of shares to redeem convertible notes	96,963	$ 61	96,902
Taxes paid related to net share settlement of equity awards (in shares)		0
Taxes paid related to net share settlement of equity awards	(3,972)		(3,972)
Foreign currency translation gain (loss)	12,844				12,844
Purchase and retirement of treasury stock (in shares)		(553)
Purchase and retirement of treasury stock	(6,999)	$ (6)	(2,861)	(4,132)
Net income	109,613			109,613
Ending balance (in shares) at Sep. 30, 2025		60,892
Ending balance at Sep. 30, 2025	$ 1,025,485	$ 609	$ 450,892	$ 612,687	$ (38,703)