Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net income	$ 6,270	$ 61,620
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation, amortization and accretion expense	1,696	2,346
Stock-based compensation expense	1,629	4,144
Deferred income taxes	0	24,080
Provision adjustments related to doubtful accounts	20	523
Provision adjustments related to product warranty	302	707
Change in fair value of financial instruments	0	(122)
Gain from change in estimate on ARO obligation	0	(845)
Reclassification of foreign currency translation adjustment	0	(744)
Recognition of previously deferred gain on sale of assets from discontinued operations	(3,804)	0
Gain on reduction of product warranty of discontinued operations	(423)	0
Gain on settlement of solar power assets and obligations	(689)	0
Gain on settlement of Newark lease	(310)	0
Net (gain) loss on disposal of equipment	(41)	237
Settlement of customer related warranty claim	0	(442)
Total non-cash adjustments	(1,620)	(59,068)
Changes in operating assets and liabilities:
Accounts receivable	(4,358)	6,828
Inventory	(6,420)	(3,026)
Other assets	120	(502)
Accounts payable	2,884	(2,979)
Accrued expenses and other current liabilities	(1,118)	(4,979)
Total change in operating assets and liabilities	(8,892)	(4,658)
Net cash used in operating activities	(4,242)	(2,106)
Cash flows from investing activities:
Purchase of equipment	(4,480)	(2,239)
(Increase) decrease in restricted cash	(844)	1,456
Receipt of escrow funds from sale of assets	1,853	0
Proceeds from disposal of property, plant and equipment	50	50
Net cash (used in) provided by investing activities	(3,421)	166,185
Cash flows from financing activities:
Payments on credit facilities	0	(26,518)
Repurchases of common stock	0	(45,618)
Proceeds from stock plans	614	1,362
Net cash provided by (used in) financing activities	614	(70,774)
Effect of exchange rate changes on foreign currency	210	137
Net (decrease) increase in cash and cash equivalents	(6,839)	93,442
Cash and cash equivalents at beginning of period	111,885	20,687
Cash and cash equivalents at end of period	105,046	114,129
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid during the period for interest	65	168
Cash paid during the period for income taxes	123	623
NON-CASH INVESTING AND FINANCING ACTIVITIES
Changes in accounts payable related to purchases of equipment	(432)	0
Issuance of common stock to Board of Directors	263	413
Photovoltaics Business [Member]
Adjustments to reconcile net income to net cash used in operating activities:
Gain on sale of business	0	(86,958)
Cash flows from investing activities:
Proceeds from sale of business	0	149,936
Digital Products Business [Member]
Adjustments to reconcile net income to net cash used in operating activities:
Gain on sale of business	0	(1,994)
Cash flows from investing activities:
Proceeds from sale of business	$ 0	$ 16,982