Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total shareholders' equity	$ 51,377	$ 60,370
Foreign currency translation adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total shareholders' equity	(5,295)	(5,623)
Retirement plan liability adjustment, net of tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total shareholders' equity	(6,531)	(7,197)
Interest rate swap agreement adjustment, net of tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total shareholders' equity	0	(30)
Total accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total shareholders' equity	$ (11,826)	$ (12,850)