Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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The net result for the period of deducting operating expenses from operating revenues.

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The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.

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Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Business Segments (Details) $ in Thousands	3 Months Ended								12 Months Ended
Business Segments (Details) $ in Thousands	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2017 USD ($) segment	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments \| segment									3
Net revenue	$ 54,677	$ 47,760	$ 32,944	$ 29,135	$ 42,409	$ 33,342	$ 22,483	$ 22,074	$ 164,516	$ 120,308	$ 104,883
Operating loss									10,425	(7,908)	(13,521)
Capital expenditures									1,256	978	610
Depreciation and amortization									2,493	2,974	3,357
Identifiable assets	191,623				118,430				191,623	118,430
Solar
Segment Reporting Information [Line Items]
Capital expenditures									1,008	235	411
Depreciation and amortization									1,544	2,014	2,940
Semiconductor
Segment Reporting Information [Line Items]
Capital expenditures									236	692	136
Depreciation and amortization									876	870	318
Polishing
Segment Reporting Information [Line Items]
Capital expenditures									12	51	63
Depreciation and amortization									$ 73	90	99
Product Concentration Risk \| Sales Revenue, Product Line \| Semiconductor
Segment Reporting Information [Line Items]
Concentration risk, percentage									25.00%
Operating Segments \| Solar
Segment Reporting Information [Line Items]
Net revenue									$ 87,031	60,946	56,689
Operating loss									6,060	(6,696)	(5,056)
Identifiable assets	97,999				42,962				97,999	42,962
Operating Segments \| Semiconductor
Segment Reporting Information [Line Items]
Net revenue									67,237	50,637	37,250
Operating loss									9,538	3,904	(1,268)
Identifiable assets	57,177				51,985				57,177	51,985
Operating Segments \| Polishing
Segment Reporting Information [Line Items]
Net revenue									10,248	8,725	10,944
Operating loss									2,617	1,588	2,250
Identifiable assets	5,078				4,819				5,078	4,819
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Operating loss									(7,790)	(6,704)	$ (9,447)
Identifiable assets	$ 31,369				$ 18,664				$ 31,369	$ 18,664