CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Net cash used in operating activities	$ (66,019)	$ (16,661)
Investing activities:
Purchases of short-term investments	(208,723)	(326,163)
Proceeds from the sale of short-term investments	298,177	302,273
Purchases of property, plant and equipment	(5,982)	(11,894)
Proceeds from land sold to BioMed		10,147
Reduction of cash due to deconsolidation of Regulus Therapeutics Inc. upon adoption of a new accounting standard		(16,228)
Acquisition of licenses and other assets	(1,755)	(2,455)
Purchases of strategic investments	(359)	(658)
Net cash (used in) provided by investing activities	81,358	(44,978)
Financing activities:
Proceeds from issuance of equity	876	1,282
Proceeds from equipment financing arrangement	1,625	3,083
Principal payments on debt obligations	(2,870)	(1,943)
Net cash (used in) provided by financing activities	(369)	2,422
Net (decrease) increase in cash and cash equivalents	14,970	(59,217)
Cash and cash equivalents at beginning of period	70,052	105,255
Cash and cash equivalents at end of period	85,022	46,038
Supplemental disclosures of cash flow information:
Interest paid	2,398	2,413
Income taxes paid	2	7,700
Supplemental disclosures of non-cash investing and financing activities:
Amounts accrued for capital and patent expenditures	1,080	831
Capitalized costs and financing liability associated with leased facility	$ 48,575