Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (23,490,000)	$ (38,890,000)	$ (53,979,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	7,577,000	11,317,000	14,510,000
Amortization	49,000	164,000	97,000
Stock based compensation	$ 3,208,000	4,672,000	6,516,000
Marketable securities recovery and accretion		(1,728,000)	(1,779,000)
(Gain) loss on disposal of equipment	$ (23,000)	1,812,000	(177,000)
Changes in operating assets and liabilities:
Accounts receivable	308,000	9,821,000	(2,923,000)
Inventories	6,617,000	7,270,000	(2,274,000)
Prepaid expenses and other assets	463,000	899,000	(433,000)
Accounts payable	(2,423,000)	(7,130,000)	(1,056,000)
Accrued and other liabilities	(2,046,000)	(784,000)	(525,000)
Net cash used in operating activities	(9,760,000)	(12,577,000)	(42,023,000)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of plant and equipment	(258,000)	(850,000)	(6,464,000)
Proceeds from sale of equipment	$ 42,000	$ 3,343,000	3,000
Purchases of marketable securities			(8,130,000)
Proceeds from sales and redemptions of marketable securities		$ 3,528,000	32,563,000
Net cash (used in) provided by investing activities	$ (216,000)	6,021,000	17,972,000
CASH FLOWS FROM FINANCING ACTIVITIES
Issuances of common stock, net of related costs	74,000	114,000	$ 20,252,000
Proceeds from bank borrowings	14,300,000	19,582,000
Repayments of bank borrowings	(15,800,000)	(15,582,000)
Payment for financing	(59,000)	$ (75,000)	$ (203,000)
Treasury stock repurchase	(3,000)
Net cash (used in) provided by financing activities	(1,488,000)	$ 4,039,000	$ 20,049,000
Net decrease in cash and cash equivalents	(11,464,000)	(2,517,000)	(4,002,000)
Cash and cash equivalents at beginning of period	18,430,000	20,947,000	24,949,000
Cash and cash equivalents at end of period	6,966,000	18,430,000	20,947,000
Net taxes paid	134,000	144,000	133,000
Interest paid	$ 34,000	$ 150,000	$ 24,000