Business Segment Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	Mar. 31, 2017 USD ($) segment	Mar. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of business segments | segment			3
Net revenues	$ 32,944	$ 22,483	$ 62,079	$ 44,557
Operating income (loss)	(1,400)	(3,607)	(1,583)	(7,535)
Identifiable assets	135,038		$ 135,038		$ 118,430
Product Concentration Risk | Sales Revenue, Product Line | Semiconductor
Segment Reporting Information [Line Items]
Concentration risk, percentage (less than)			25.00%
Operating Segments | Solar
Segment Reporting Information [Line Items]
Net revenues	16,555	9,801	$ 27,979	19,344
Operating income (loss)	(1,878)	(2,266)	(2,901)	(4,130)
Identifiable assets	60,610		60,610		42,962
Operating Segments | Semiconductor
Segment Reporting Information [Line Items]
Net revenues	13,443	10,507	29,146	21,206
Operating income (loss)	1,403	(119)	3,763	(279)
Identifiable assets	52,670		52,670		51,985
Operating Segments | Polishing
Segment Reporting Information [Line Items]
Net revenues	2,946	2,175	4,954	4,007
Operating income (loss)	503	386	967	555
Identifiable assets	4,783		4,783		4,819
Non-Segment
Segment Reporting Information [Line Items]
Operating income (loss)	(1,428)	$ (1,608)	(3,412)	$ (3,681)
Identifiable assets	$ 16,975		$ 16,975		$ 18,664