Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-in Capital	Additional Paid-in Capital Cumulative Effect, Period of Adoption, Adjustment	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Loss
Beginning Balance (in shares) at Sep. 30, 2020			55,303
Beginning Balance at Sep. 30, 2020	$ 649,127		$ 551	$ 398,475		$ 318,169		$ (68,068)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation	524			524
Release of restricted stock (in shares)			296
Release of restricted stock	5		$ 5
Taxes paid related to net share settlement of equity awards	(730)			(730)
Foreign currency translation gain (loss)	11,277							11,277
Net income	4,299					4,299
Ending Balance (in shares) at Dec. 31, 2020			55,599
Ending Balance at Dec. 31, 2020	664,502		$ 556	398,269		322,468		(56,791)
Beginning Balance (in shares) at Sep. 30, 2020			55,303
Beginning Balance at Sep. 30, 2020	649,127		$ 551	398,475		318,169		(68,068)
Ending Balance (in shares) at Sep. 30, 2021			56,057
Ending Balance at Sep. 30, 2021	672,238	$ (37,406)	$ 560	403,312	$ (64,263)	326,781	$ 26,857	(58,415)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation	1,698			1,698
Release of restricted stock (in shares)			257
Release of restricted stock	3		$ 3
Taxes paid related to net share settlement of equity awards	(792)			(792)
Foreign currency translation gain (loss)	3,039							3,039
Net income	15,721					15,721
Ending Balance (in shares) at Dec. 31, 2021			56,314
Ending Balance at Dec. 31, 2021	$ 654,501		$ 563	$ 339,955		$ 369,359		$ (55,376)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible Enumeration]	Accounting Standards Update 2020-06