CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 84,685	$ 128,797
Short-term investments	580,538	650,386
Contracts receivable	108,043	11,356
Inventories	7,489	6,899
Investment in Regulus Therapeutics Inc.	2,414	24,792
Other current assets	14,763	14,773
Total current assets	797,932	837,003
Property, plant and equipment, net	92,845	90,233
Patents, net	20,365	19,316
Deposits and other assets	1,325	1,348
Total assets	912,467	947,900
Current liabilities:
Accounts payable	21,120	28,355
Accrued compensation	24,186	16,065
Accrued liabilities	36,013	28,105
Current portion of long-term obligations	1,185	9,029
Current portion of deferred contract revenue	51,280	67,322
Total current liabilities	133,784	148,876
Long-term deferred contract revenue	91,198	134,306
Long-term obligations, less current portion	14,926	2,341
Long-term financing liability for leased facility	72,359	72,217
Total liabilities	812,902	747,110
Stockholders' equity:
Common stock, $0.001 par value; 300,000,000 shares authorized, 121,636,273 and 120,351,480 shares issued and outstanding at December 31, 2016 and December 31, 2015, respectively	122	120
Additional paid-in capital	1,311,229	1,309,107
Accumulated other comprehensive income (loss)	(30,358)	(13,565)
Accumulated deficit	(1,181,428)	(1,094,872)
Total stockholders' equity	99,565	200,790
Total liabilities and stockholders' equity	912,467	947,900
1 Percent Convertible Senior Notes [Member]
Current liabilities:
Convertible senior notes	500,511	339,847
2 3/4 Percent Convertible Senior Notes [Member]
Current liabilities:
Convertible senior notes	$ 124	$ 49,523