CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating activities:
Net income (loss)	$ (3,854,000)	$ 1,260,000
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation of fixed assets and amortization of intangibles	3,165,000	2,743,000
Amortization of unfavorable lease obligation and debt issuance costs, net	120,000	122,000
Amortization of debt discount	1,022,000	1,035,000
Stock-based compensation	8,490,000	7,517,000
Changes in operating assets and liabilities:
Restricted cash	0	1,509,000
Accounts receivable, net	(46,000)	(2,145,000)
Inventories, net	(2,099,000)	(7,001,000)
Prepaid expenses and other assets	(2,917,000)	372,000
Accounts payable and accrued expenses	(6,227,000)	(5,679,000)
Royalty interest obligation	0	(276,000)
Other liabilities	(419,000)	29,000
Deferred revenue	(356,000)	(356,000)
Net cash used in operating activities	(3,121,000)	(870,000)
Investing activities:
Purchases of fixed assets	(7,053,000)	(7,874,000)
Purchases of investments	(67,843,000)	(49,937,000)
Sales of investments	54,925,000	59,631,000
Payment of contingent consideration	(1,904,000)	(1,620,000)
Net cash provided by (used in) investing activities	(21,875,000)	200,000
Financing activities:
Proceeds from exercise of stock options	3,041,000	4,047,000
Net cash provided by financing activities	3,041,000	4,047,000
Net (decrease) increase in cash and cash equivalents	(21,955,000)	3,377,000
Cash and cash equivalents, beginning of period	56,984,000	37,520,000
Cash and cash equivalents, end of period	35,029,000	40,897,000
Supplemental cash flow information:
Cash paid for interest, including royalty interest obligation	1,926,000	2,297,000
Cash paid for income taxes, net of refunds	142,000	160,000
Non-cash investing and financing activities:
Net increase in accrued fixed assets	$ 1,554,000	$ 1,363,000