CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 128,797	$ 142,998
Short-term investments	650,386	585,834
Contracts receivable	11,356	3,903
Inventories	6,899	6,290
Investment in Regulus Therapeutics Inc.	24,792	81,881
Other current assets	14,773	15,691
Total current assets	837,003	836,597
Property, plant and equipment, net	90,233	88,958
Patents, net	19,316	17,186
Deposits and other assets	9,553	13,068
Total assets	956,105	955,809
Current liabilities:
Accounts payable	28,355	17,984
Accrued compensation	16,065	12,302
Accrued liabilities	28,105	30,451
Current portion of long-term obligations	9,029	2,882
Current portion of deferred contract revenue	67,322	51,713
Total current liabilities	148,876	115,332
Long-term deferred contract revenue	134,306	127,797
Long-term obligations, less current portion	2,341	7,669
Long-term financing liability for leased facility	72,217	71,731
Total liabilities	755,315	698,029
Stockholders' equity:
Common stock, $0.001 par value; 300,000,000 shares authorized, 120,351,480 and 118,442,726 shares issued and outstanding at December 31, 2015 and December 31, 2014, respectively	120	118
Additional paid-in capital	1,309,107	1,224,509
Accumulated other comprehensive income (loss)	(13,565)	39,747
Accumulated deficit	(1,094,872)	(1,006,594)
Total stockholders' equity	200,790	257,780
Total liabilities and stockholders' equity	956,105	955,809
1 Percent Convertible Senior Notes [Member]
Current liabilities:
Convertible senior notes	347,214	327,486
2 3/4 Percent Convertible Senior Notes [Member]
Current liabilities:
Convertible senior notes	$ 50,361	$ 48,014