Major Customers and Foreign Sales (Details) - Customer	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Revenue, Major Customer [Line Items]
Revenue, number of major customers			2
Revenues, percentage	100.00%	100.00%	100.00%
Total Americas
Revenue, Major Customer [Line Items]
Revenues, percentage	12.00%	20.00%	26.00%
United States
Revenue, Major Customer [Line Items]
Revenues, percentage			24.00%
Other
Revenue, Major Customer [Line Items]
Revenues, percentage			2.00%
Total Asia
Revenue, Major Customer [Line Items]
Revenues, percentage	75.00%	68.00%	60.00%
Taiwan
Revenue, Major Customer [Line Items]
Revenues, percentage			13.00%
Malaysia
Revenue, Major Customer [Line Items]
Revenues, percentage			13.00%
China
Revenue, Major Customer [Line Items]
Revenues, percentage			26.00%
Other
Revenue, Major Customer [Line Items]
Revenues, percentage			8.00%
Total Europe
Revenue, Major Customer [Line Items]
Revenues, percentage	13.00%	12.00%	14.00%
Germany
Revenue, Major Customer [Line Items]
Revenues, percentage			5.00%
Other
Revenue, Major Customer [Line Items]
Revenues, percentage			9.00%
Customer Number One
Revenue, Major Customer [Line Items]
Revenue, major customer, percentage		11.00%	15.00%
Customer Number Two
Revenue, Major Customer [Line Items]
Revenue, major customer, percentage			11.00%
Sales Revenue, Net | Geographic Concentration Risk | United States
Revenue, Major Customer [Line Items]
Revenue, major customer, percentage	11.00%	17.00%
Sales Revenue, Net | Geographic Concentration Risk | Other
Revenue, Major Customer [Line Items]
Revenue, major customer, percentage	1.00%	3.00%
Sales Revenue, Net | Geographic Concentration Risk | Taiwan
Revenue, Major Customer [Line Items]
Revenue, major customer, percentage	12.00%	15.00%
Sales Revenue, Net | Geographic Concentration Risk | Malaysia
Revenue, Major Customer [Line Items]
Revenue, major customer, percentage	9.00%	18.00%
Sales Revenue, Net | Geographic Concentration Risk | China
Revenue, Major Customer [Line Items]
Revenue, major customer, percentage	47.00%	28.00%
Sales Revenue, Net | Geographic Concentration Risk | Other
Revenue, Major Customer [Line Items]
Revenue, major customer, percentage	7.00%	7.00%
Sales Revenue, Net | Geographic Concentration Risk | Germany
Revenue, Major Customer [Line Items]
Revenue, major customer, percentage	5.00%	3.00%
Sales Revenue, Net | Geographic Concentration Risk | Other
Revenue, Major Customer [Line Items]
Revenue, major customer, percentage	8.00%	9.00%