CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 112,534	$ 128,797
Short-term investments	551,556	650,386
Contracts receivable	746	11,356
Inventories	7,668	6,899
Investment in Regulus Therapeutics Inc.	8,217	24,792
Other current assets	17,250	14,773
Total current assets	697,971	837,003
Property, plant and equipment, net	90,602	90,233
Patents, net	21,152	19,316
Deposits and other assets	1,384	1,348
Total assets	811,109	947,900
Current liabilities:
Accounts payable	17,583	28,355
Accrued compensation	7,441	16,065
Accrued liabilities	18,976	28,105
Current portion of long-term obligations	8,608	9,029
Current portion of deferred contract revenue	58,473	67,322
Total current liabilities	111,081	148,876
Long-term deferred contract revenue	112,436	134,306
Long-term obligations, less current portion	2,420	2,341
Long-term financing liability for leased facility	72,286	72,217
Total liabilities	699,896	747,110
Stockholders' equity:
Common stock, $0.001 par value; 300,000,000 shares authorized, 120,852,720 and 120,351,480 shares issued and outstanding at June 30, 2016 and December 31, 2015, respectively	121	120
Additional paid-in capital	1,352,589	1,309,107
Accumulated other comprehensive loss	(26,853)	(13,565)
Accumulated deficit	(1,214,644)	(1,094,872)
Total stockholders' equity	111,213	200,790
Total liabilities and stockholders' equity	811,109	947,900
1 Percent Convertible Senior Notes [Member]
Current liabilities:
Convertible senior notes	350,800	339,847
2 3/4 Percent Convertible Senior Notes [Member]
Current liabilities:
Convertible senior notes	$ 50,873	$ 49,523