Accumulated Other Comprehensive Loss - Components (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 30,428	$ 33,802
Ending Balance	29,534	30,428
Accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(12,593)	(10,825)
Change in period	565	(1,828)
Tax effect of change in period	33	60
Ending Balance	(11,995)	(12,593)
Effect of Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(5,111)	(4,346)
Change in period	415	(765)
Ending Balance	(4,696)	(5,111)
Minimum Pension Liability
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(7,482)	(6,479)
Change in period	150	(1,063)
Tax effect of change in period	33	60
Ending Balance	$ (7,299)	$ (7,482)