Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accummulated Other Comprehensive Income/(Loss)
Balance (in shares) at Sep. 30, 2018		12,281			(806)
Balance at Sep. 30, 2018	$ 301,644	$ 123	$ 56,769	$ 291,530	$ (24,999)	$ (21,779)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	(2,695)			(2,695)
Foreign currency translation adjustments	(4,088)					(4,088)
Stock-based compensation (in shares)		41
Stock-based compensation	1,220		1,220
Shares withheld in lieu of employee tax withholding	(731)		(731)
Dividends paid	(2,992)			(2,992)
Balance (in shares) at Dec. 31, 2018		12,322			(806)
Balance at Dec. 31, 2018	292,358	$ 123	57,258	285,843	$ (24,999)	(25,867)
Balance (in shares) at Sep. 30, 2019		12,373			(806)
Balance at Sep. 30, 2019	299,153	$ 124	59,153	289,422	$ (24,999)	(24,547)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,775			2,775
Foreign currency translation adjustments	2,387					2,387
Stock-based compensation (in shares)		30
Stock-based compensation	982		982
Shares withheld in lieu of employee tax withholding	(611)		(611)
Dividends paid	(3,013)			(3,013)
Balance (in shares) at Dec. 31, 2019		12,403			(806)
Balance at Dec. 31, 2019	$ 301,673	$ 124	$ 59,524	$ 289,184	$ (24,999)	$ (22,160)