CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Revenue:
Research and development revenue under collaborative agreements	$ 22,455	$ 119,658	$ 57,670	$ 181,551
Licensing and royalty revenue	16,015	770	17,675	1,461
Total revenue	38,470	120,428	75,345	183,012
Expenses:
Research, development and patent expenses	77,573	68,007	158,536	132,454
General and administrative	9,824	7,775	20,386	15,241
Total operating expenses	87,397	75,782	178,922	147,695
Income (loss) from operations	(48,927)	44,646	(103,577)	35,317
Other income (expense):
Investment income	1,466	918	2,921	1,762
Interest expense	(9,625)	(9,127)	(19,115)	(18,148)
Income (loss) before income tax expense	(57,086)	36,437	(119,771)	18,931
Income tax benefit (expense)	231	(789)	(1)	0
Net income (loss)	$ (56,855)	$ 35,648	$ (119,772)	$ 18,931
Basic net income (loss) per share (in dollars per share)	$ (0.47)	$ 0.30	$ (0.99)	$ 0.16
Diluted net income (loss) per share (in dollars per share)	$ (0.47)	$ 0.29	$ (0.99)	$ 0.15
Shares used in computing basic net income (loss) per share (in shares)	120,798	119,742	120,698	119,348
Shares used in computing diluted net income (loss) per share (in shares)	120,798	127,779	120,698	124,061