CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 296,540	$ 124,482
Short-term investments	294,212	249,964
Contracts receivable	2,024	522
Inventories	8,309	6,121
Investment in Regulus Therapeutics Inc.	62,190	33,622
Other current assets	5,786	8,727
Total current assets	669,061	423,438
Property, plant and equipment, net	88,312	91,084
Licenses, net	5,528	6,579
Patents, net	20,149	18,646
Deposits and other assets	5,601	5,939
Total assets	788,651	545,686
Current liabilities:
Accounts payable	9,461	10,239
Accrued compensation	7,031	7,878
Accrued liabilities	16,514	15,401
Accrued income taxes	8,727
Current portion of long-term obligations	4,853	4,879
Current portion of deferred contract revenue	40,409	35,925
Total current liabilities	86,995	74,322
Long-term deferred contract revenue	75,184	66,656
2 3/4 percent convertible senior notes	147,099	143,990
Long-term obligations, less current portion	7,382	7,402
Long-term financing liability for leased facility	70,910	70,550
Total liabilities	387,570	362,920
Stockholders' equity:
Common stock, $0.001 par value; 200,000,000 shares authorized, 114,291,999 and 101,481,134 shares issued and outstanding at June 30, 2013 and December 31, 2012, respectively	114	102
Additional paid-in capital	1,292,745	1,077,150
Accumulated other comprehensive gain	26,986	12,480
Accumulated deficit	(918,764)	(906,966)
Total stockholders' equity	401,081	182,766
Total liabilities and stockholders' equity	$ 788,651	$ 545,686