Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities:
Net loss	$ (16,750)	$ (77,069)	$ (81,153)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	3,084	2,536	2,405
Impairment loss on assets held for sale	1,100
Non-cash equity-based compensation expense	7,024	10,038	14,523
Non-cash income tax benefit	(854)	(1,170)	(481)
Amortization of premium/discount on purchased securities	2,808	3,639	1,679
Fair value adjustment of settlement rights			788
Losses (gains) on investments, net	1,466	193	(408)
Changes in operating assets and liabilities:
Accounts receivable, net	(478)	(147)	21,565
Inventories	5,891	1,506	(6,675)
Receivable from collaboration	165	13	(441)
Prepaid and other current assets	75	1,661	(2,477)
Accounts payable and accrued expenses	(12,195)	1,698	2,745
Deferred revenues	7,912	(6,353)	46,697
Other long-term liabilities	(405)	(349)	(294)
Total adjustments	15,593	13,265	79,626
Net cash used in operating activities	(1,157)	(63,804)	(1,527)
Cash flows from investing activities:
Proceeds from sales or maturities of investments	133,061	141,095	160,079
Purchase of investments	(149,406)	(126,585)	(262,597)
Capital expenditures	(47)	(507)	(1,223)
Net cash (used in) provided by investing activities	(16,392)	14,003	(103,741)
Cash flows from financing activities:
Proceeds from the exercise of stock options	98	121	1,337
Proceeds from the issuance of common stock, net of underwriting discounts and other expenses			165,559
Proceeds from the issuance of common stock under ESPP	270	508	892
Net cash provided by financing activities	368	629	167,788
Net (decrease) increase in cash and cash equivalents	(17,181)	(49,172)	62,520
Cash and cash equivalents at beginning of the year	63,474	112,646	50,126
Cash and cash equivalents at end of the year	46,293	63,474	112,646
Non-cash investing activities:
Accrued construction in progress	$ 228