CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 119,487	$ 142,998
Short-term investments	635,447	585,834
Contracts receivable	3,264	3,903
Inventories	6,782	6,290
Investment in Regulus Therapeutics Inc.	60,604	81,881
Other current assets	29,868	15,691
Total current assets	855,452	836,597
Property, plant and equipment, net	89,692	88,958
Licenses, net	1,753	2,690
Patents, net	19,060	17,186
Deposits and other assets	10,301	10,378
Total assets	976,258	955,809
Current liabilities:
Accounts payable	10,954	17,984
Accrued compensation	7,915	12,302
Accrued liabilities	23,753	30,451
Current portion of long-term obligations	1,225	2,882
Current portion of deferred contract revenue	58,285	51,713
Total current liabilities	102,132	115,332
Long-term deferred contract revenue	108,128	127,797
Long-term obligations, less current portion	7,392	7,669
Long-term financing liability for leased facility	71,968	71,731
Total liabilities	675,938	698,029
Stockholders' equity:
Common stock, $0.001 par value; 300,000,000 shares authorized, 119,881,615 and 118,442,726 shares issued and outstanding at June 30, 2015 and December 31, 2014, respectively	120	118
Additional paid-in capital	1,269,452	1,224,509
Accumulated other comprehensive income	18,411	39,747
Accumulated deficit	(987,663)	(1,006,594)
Total stockholders' equity	300,320	257,780
Total liabilities and stockholders' equity	976,258	955,809
1 Percent Convertible Senior Notes [Member]
Current liabilities:
Convertible senior notes	337,158	327,486
2 3/4 Percent Convertible Senior Notes [Member]
Current liabilities:
Convertible senior notes	$ 49,160	$ 48,014