Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net (loss) income	$ (17,453)	$ 8,235	$ 8,266
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	5,617	3,757	2,506
Stock-based compensation expense	3,648	3,602	2,086
Provision adjustments related to doubtful accounts	599	23	23
Provision adjustments related to product warranty	431	573	376
Impairments of equipment	0	506	0
Recognition of previously deferred gain on sale of assets from discontinued operations	0	0	(3,804)
Net loss (gain) on disposal of equipment	34	(456)	(41)
Other	412	(50)	(1,422)
Total non-cash adjustments	10,741	7,955	(276)
Changes in operating assets and liabilities:
Accounts receivable	2,372	(3,859)	(1,171)
Inventory	5,067	(140)	(10,904)
Other assets	(3,925)	(4,455)	148
Accounts payable	477	2,095	3,179
Accrued expenses and other current liabilities	4,191	1,870	(4,794)
Total change in operating assets and liabilities	8,182	(4,489)	(13,542)
Net cash provided by (used in) operating activities	1,470	11,701	(5,552)
Cash flows from investing activities:
Purchase of equipment	(6,583)	(9,600)	(5,779)
Receipt of escrow funds from sale of assets	0	0	1,853
Proceeds from disposal of property, plant and equipment	82	474	100
Net cash used in investing activities	(6,501)	(9,126)	(3,826)
Cash flows from financing activities:
Payment of special dividend	0	0	(39,214)
Proceeds from stock plans	770	1,306	960
Tax withholding paid on behalf of employees for stock-based awards	(1,257)	0	0
Net cash (used in) provided by financing activities	(487)	1,306	(38,254)
Effect of exchange rate changes on foreign currency	(41)	3	242
Net (decrease) increase in cash, cash equivalents and restricted cash	(5,559)	3,884	(47,390)
Cash, cash equivalents and restricted cash at beginning of period	68,754	64,870	112,260
Cash, cash equivalents and restricted cash at end of period	63,195	68,754	64,870
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid during the period for interest	63	71	88
Cash paid during the period for income taxes	131	114	124
NON-CASH INVESTING AND FINANCING ACTIVITIES
Changes in accounts payable related to purchases of equipment	755	(861)	282
Issuance of common stock to Board of Directors	$ 0	$ 331	$ 263