Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Noncontrolling Interest
Beginning balance (shares) at Sep. 30, 2018		54,585
Beginning Balance at Sep. 30, 2018	$ 739,408	$ 546	$ 397,927	$ 386,622	$ (42,356)	$ (3,331)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation	2,247		2,247
Release of restricted stock (shares)		860
Release of restricted stock	8	$ 8
Taxes paid related to net share settlement of equity awards	(3,288)		(3,288)
Transfer of subsidiary shares to noncontrolling interest			3,195			(3,195)
Foreign currency translation gain (loss)	(6,383)				(6,383)
Net income (loss)	(3,843)			(3,366)		(477)
Ending balance (shares) at Dec. 31, 2018		55,445
Ending Balance at Dec. 31, 2018	728,149	$ 554	400,081	383,256	(48,739)	$ (7,003)
Beginning balance (shares) at Sep. 30, 2019		55,535
Beginning Balance at Sep. 30, 2019	744,949	$ 556	407,628	389,163	(52,398)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation	1,695		1,695
Release of restricted stock (shares)		463
Release of restricted stock	5	$ 5
Taxes paid related to net share settlement of equity awards	(1,395)		(1,395)
Foreign currency translation gain (loss)	6,071				6,071
Purchase and retirement of treasury stock (in shares)		(142)
Purchase and retirement of treasury stock	(963)	$ (2)	(488)	(473)
Net income (loss)	1,238			1,238
Ending balance (shares) at Dec. 31, 2019		55,856
Ending Balance at Dec. 31, 2019	$ 751,600	$ 559	$ 407,440	$ 389,928	$ (46,327)