Summary of Significant Accounting Policies - Effects of Adoption of 2014-09 (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Oct. 01, 2018	Sep. 30, 2018
Statement of Financial Position [Abstract]
Contract asset	$ 10,262		$ 10,140	$ 0
Inventories, net	11,813		11,727	18,269
Contract liabilities (included within accrued liabilities)	441			0
Deferred income taxes	2,332			2,413
Retained earnings	39,414		40,695	37,097
Income Statement [Abstract]
Net sales	29,067	$ 24,251
Cost of goods sold	26,330	22,222
Loss before income tax benefit	(1,796)	(1,151)
Net loss	$ (1,282)	$ (911)
Basic net loss per share (in dollars per share)	$ (0.23)	$ (0.17)
Diluted net loss per share (in dollars per share)	$ (0.23)	$ (0.17)
Previous Accounting Method
Statement of Financial Position [Abstract]
Contract asset	$ 0			0
Inventories, net	18,720			18,269
Contract liabilities (included within accrued liabilities)	1,000
Deferred income taxes	2,332
Retained earnings	35,499			$ 37,097
Income Statement [Abstract]
Net sales	28,386
Cost of goods sold	25,965
Loss before income tax benefit	(2,112)
Net loss	$ (1,598)
Basic net loss per share (in dollars per share)	$ (0.29)
Diluted net loss per share (in dollars per share)	$ (0.29)
Accounting Standards Update 2014-09 | Effect of Accounting Change
Statement of Financial Position [Abstract]
Contract asset	$ 10,262		10,140
Inventories, net	(6,907)		(6,542)
Contract liabilities (included within accrued liabilities)	(559)
Deferred income taxes	0
Retained earnings	3,915		$ 3,598
Income Statement [Abstract]
Net sales	681
Cost of goods sold	365
Loss before income tax benefit	316
Net loss	$ 316
Basic net loss per share (in dollars per share)	$ 0.06
Diluted net loss per share (in dollars per share)	$ 0.06