Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Sep. 30, 2015
Property Plant And Equipment [Abstract]
Land and land improvements	$ 8,572				$ 8,552	$ 8,714
Building and building improvements	31,034				30,756	30,955
Machinery and equipment	53,185				51,034	44,905
Furniture and fixtures	1,352				1,323	1,260
Transportation equipment	31				28	29
Tools and molds	2,181				2,165	1,864
Leasehold improvements						43
Construction in progress	1,135				807	6,135
Property plant and equipment gross	97,490				94,665	93,905
Accumulated depreciation and impairment	(60,091)				(49,933)	(45,196)
Property plant and equipment net	$ 37,399	$ 43,432	$ 44,484	$ 43,477	$ 44,732	$ 48,709