Summary of Significant Accounting Policies - Effects of Adoption of 2014-09 (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Oct. 01, 2018
Statement of Financial Position [Abstract]
Contract asset	$ 10,349	$ 0	$ 10,140
Inventories, net	10,509	18,269	11,727
Contract liabilities (included within accrued liabilities)	382		0
Deferred income taxes	1,718	2,413
Retained earnings	33,148	37,097	40,695
Income Statement [Abstract]
Net sales	112,454	111,212
Cost of goods sold	101,817	101,110
Net loss	$ (7,506)	$ (7,170)
Net Loss per share (basic and diluted) (in dollars per share)	$ (1.35)	$ (1.30)
Accounting Standards Update 2014-09
Income Statement [Abstract]
Cost of goods sold	$ (340)
Previous Accounting Method
Statement of Financial Position [Abstract]
Contract asset	0	$ 0
Inventories, net	16,592	18,269
Contract liabilities (included within accrued liabilities)	537
Deferred income taxes	1,718
Retained earnings	28,727	$ 37,097
Income Statement [Abstract]
Net sales	112,090
Cost of goods sold	102,276
Net loss	$ (8,329)
Net Loss per share (basic and diluted) (in dollars per share)	$ (1.50)
Effect of Accounting Changes | Accounting Standards Update 2014-09
Statement of Financial Position [Abstract]
Contract asset	$ 10,349		10,140
Inventories, net	(6,083)		(6,542)
Contract liabilities (included within accrued liabilities)	(155)
Deferred income taxes	0
Retained earnings	4,421		$ 3,598
Income Statement [Abstract]
Net sales	364
Cost of goods sold	(459)
Net loss	$ 823
Net Loss per share (basic and diluted) (in dollars per share)	$ 0.15