CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 94,081	$ 159,973
Short-term investments	496,754	496,788
Contracts receivable	41,941	11,102
Inventories	7,776	8,033
Investment in Regulus Therapeutics Inc.	56,678	52,096
Other current assets	8,567	7,518
Total current assets	705,797	735,510
Property, plant and equipment, net	86,321	86,198
Licenses, net	3,631	4,572
Patents, net	16,729	15,517
Deposits and other assets	5,299	5,359
Total assets	817,777	847,156
Current liabilities:
Accounts payable	13,453	11,009
Accrued compensation	6,430	12,168
Accrued liabilities	25,166	22,092
Current portion of long-term obligations	4,207	4,408
Current portion of deferred contract revenue	51,560	48,135
Total current liabilities	100,816	97,812
Long-term deferred contract revenue	120,387	142,790
2 3/4 percent convertible senior notes	153,700	150,334
Long-term obligations, less current portion	4,510	6,542
Long-term financing liability for leased facility	71,504	71,288
Total liabilities	450,917	468,766
Stockholders' equity:
Common stock, $0.001 par value; 300,000,000 shares authorized, 117,669,618 and 116,471,371 shares issued and outstanding at June 30, 2014 and December 31, 2013, respectively	118	116
Additional paid-in capital	1,352,994	1,324,804
Accumulated other comprehensive income	24,719	21,080
Accumulated deficit	(1,010,971)	(967,610)
Total stockholders' equity	366,860	378,390
Total liabilities and stockholders' equity	$ 817,777	$ 847,156