Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated 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, 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	(1,737)
Foreign currency translation adjustments	(2,368)
Balance (in shares) at Mar. 31, 2019		12,353			(806)
Balance at Mar. 31, 2019	292,294	$ 124	57,511	283,805	$ (24,999)	(24,147)
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)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	958			958
Foreign currency translation adjustments	1,720					1,720
Stock-based compensation (in shares)		17
Stock-based compensation	670	$ 1	669
Shares withheld in lieu of employee tax withholding	(416)		(416)
Issuance of restricted stock (in shares)		14
Issuance of restricted stock	0	$ 0
Dividends paid	(2,996)			(2,996)
Balance (in shares) at Mar. 31, 2019		12,353			(806)
Balance at Mar. 31, 2019	292,294	$ 124	57,511	283,805	$ (24,999)	(24,147)
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)
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	10,196
Foreign currency translation adjustments	(4,529)
Balance (in shares) at Mar. 31, 2020		12,420			(806)
Balance at Mar. 31, 2020	300,131	$ 124	60,492	293,590	$ (24,999)	(29,076)
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)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	7,421			7,421
Foreign currency translation adjustments	(6,916)					(6,916)
Stock-based compensation (in shares)		0
Stock-based compensation	968	$ 0	968
Issuance of restricted stock (in shares)		17
Dividends paid	(3,015)			(3,015)
Balance (in shares) at Mar. 31, 2020		12,420			(806)
Balance at Mar. 31, 2020	$ 300,131	$ 124	$ 60,492	$ 293,590	$ (24,999)	$ (29,076)