Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating Activities
Net income (loss)	$ (29,781)	$ 70,726	$ 3,896
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Depreciation and amortization	2,561	399	520
Amortization of investments	331	21	(81)
Gain on bargain purchase	(92)
Allowance for inventory obsolescence	584	(809)	337
Loss on disposal of property and equipment	28
Stock-based compensation	5,070	3,869	2,031
Changes in assets and liabilities:
Accounts receivable	807	1,673	(1,316)
Receivables from collaborative partners	(1,943)	(7,881)	(98)
Inventories	(2,346)	(3,016)	658
Prepaid and other assets	(1,509)	(4,031)	(145)
Accounts payable and other accrued liabilities	5,661	7,811	3,075
Accrued compensation	1,780	597	234
Deferred revenue	(12,136)	(11,708)	(11,492)
Net cash (used in) provided by operating activities	(30,985)	57,651	(2,381)
Investing Activities
Purchases of property and equipment	(6,880)	(698)	(179)
Acquisition of Business	(26,435)
Purchases of marketable securities	(38,462)	(195,162)	(71,325)
Maturities of marketable securities	61,405	58,495	64,531
Sales of marketable securities	43,704	75,177	7,485
Net cash provided by (used in) investing activities	33,332	(62,188)	512
Financing Activities
Principal payments on long-term debt		(2,244)	(3,843)
Proceeds from issuance of common stock	2,686	8,298	1,417
Net cash provided by financing activities	2,686	6,054	(2,426)
Net increase (decrease) in cash and cash equivalents	5,033	1,517	(4,295)
Cash and cash equivalents at beginning of period	24,043	22,526	26,821
Cash and cash equivalents at end of period	29,076	24,043	22,526
Supplemental Disclosure of Cash Flow Information
Interest		133	512
Taxes	$ 144	$ (421)	$ (5)