CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net loss	$ (5,948)	$ (13,064)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and amortization	2,935	2,742
Impairment loss on assets held for sale		800
Amortization of premium/discount on purchased securities	2,076	2,181
Write-off of inventory	502	598
Non-cash equity-based compensation expense	5,886	5,312
Non-cash income tax benefit		(793)
(Gains) losses on sale of assets	(865)
(Gains) losses on investments, net	(36)	1,469
Change in fair value of contingent consideration	279
Changes in operating assets and liabilities:
Accounts receivable, net	(2,368)	(1,431)
Inventories	640	3,262
Receivable from collaboration	13	(349)
Prepaid and other current assets	313	(1,339)
Accounts payable and accrued expenses	(7,033)	(13,386)
Deferred revenues	(4,999)	(3,668)
Other long-term liabilities	(305)	(302)
Total adjustments	(2,962)	(4,904)
Net cash used in operating activities	(8,910)	(17,968)
Cash flows from investing activities:
Proceeds from sales or maturities of investments	84,454	102,540
Purchase of investments	(88,629)	(105,305)
Acquisition of MuGard Rights and inventory	(3,434)
Proceeds from sale of assets	977
Change in restricted cash	(400)
Capital expenditures	(1,206)	(47)
Net cash used in investing activities	(8,238)	(2,812)
Cash flows from financing activities:
Payment of contingent consideration	(4)
Proceeds from the exercise of stock options	1,629	56
Proceeds from the issuance of common stock under ESPP	176	150
Net cash provided by financing activities	1,801	206
Net decrease in cash and cash equivalents	(15,347)	(20,574)
Cash and cash equivalents at beginning of the period	46,293	63,474
Cash and cash equivalents at end of the period	30,946	42,900
Supplemental data:
Accrued fixed asset purchases	$ 193