CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
Net cash used in operating activities	$ (10,576)	$ (6,711)
Investing activities:
Purchases of short-term investments	(64,552)	(61,841)
Proceeds from the sale of short-term investments	49,076	61,781
Purchases of property, plant and equipment	(222)	(113)
Acquisition of licenses and other assets, net	(702)	(349)
Proceeds from sale of strategic investments	1,094
Net cash used in investing activities	(15,306)	(522)
Financing activities:
Proceeds from issuance of equity	11,823	638
Principal payments on debt and capital lease obligations	(2,773)	(2,491)
Net cash provided by (used in) financing activities	9,050	(1,853)
Net decrease in cash and cash equivalents	(16,832)	(9,086)
Cash and cash equivalents at beginning of period	124,482	65,477
Cash and cash equivalents at end of period	107,650	56,391
Supplemental disclosures of cash flow information:
Interest paid	113	2,211
Income taxes paid	2
Supplemental disclosures of non-cash investing and financing activities:
Amounts accrued for capital and patent expenditures	$ 715	$ 844