Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total shareholders' equity	$ 57,111	$ 60,370
Foreign currency translation adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total shareholders' equity	(6,671)	(5,623)
Retirement plan liability adjustment, net of tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total shareholders' equity	(6,963)	(7,197)
Interest rate swap agreement adjustment, net of tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total shareholders' equity	(14)	(30)
Total accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total shareholders' equity	$ (13,648)	$ (12,850)