Business Segment Information (Details) $ in Thousands	3 Months Ended
	Dec. 31, 2016 USD ($) segment	Dec. 31, 2015 USD ($)	Sep. 30, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of business segments | segment	3
Net revenues	$ 29,135	$ 22,074
Operating income (Loss)	(180)	(3,929)
Identifiable assets	$ 115,918		$ 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	$ 11,424	9,543
Operating income (Loss)	(1,023)	(1,864)
Identifiable assets	43,334		42,962
Operating Segments | Semiconductor
Segment Reporting Information [Line Items]
Net revenues	15,703	10,700
Operating income (Loss)	2,361	(160)
Identifiable assets	51,898		51,985
Operating Segments | Polishing
Segment Reporting Information [Line Items]
Net revenues	2,008	1,831
Operating income (Loss)	464	169
Identifiable assets	4,906		4,819
Non-Segment
Segment Reporting Information [Line Items]
Operating income (Loss)	(1,982)	$ (2,074)
Identifiable assets	$ 15,780		$ 18,664