Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 488,944	$ 502,677
Receivable from collaboration partner	277,612	184,737
Deferred income tax assets	22,353	21,987
Prepaid expenses and other current assets	15,946	12,264
Restricted cash	930	203
Total current assets	805,785	721,868
Property and equipment, net	49,018	41,161
Intangible assets	101,000	101,000
Deferred income tax assets, non-current	35,628	15,176
Restricted cash, net of current	12,206	11,562
Goodwill	10,000	10,000
Other non-current assets	6,957	10,852
Total assets	1,020,594	911,619
Current liabilities:
Accounts payable, accrued expenses and other current liabilities	132,258	106,128
Contingent consideration	10,000	10,000
Deferred revenue		2,822
Current portion of build-to-suit lease obligation	235	698
Current portion of Convertible Notes, net of unamortized discount of $- and $1 at September 30, 2015 and December 31, 2014, respectively		4
Total current liabilities	217,493	119,652
Convertible Notes, net of unamortized discount of $- and $36,598 at September 30, 2015 and December 31, 2014, respectively		222,140
Contingent consideration	102,799	96,000
Build-to-suit lease obligation, excluding current portion	16,905	18,711
Other non-current liabilities	11,729	5,817
Total liabilities	$ 348,926	$ 462,320
Commitments and contingencies (Note 14)
Stockholders' equity:
Preferred stock, $0.01 par value per share; 1,000,000 shares authorized; no shares issued and outstanding
Common stock, $0.01 par value per share; 340,000,000 shares authorized; 163,575,512 and 156,234,454 shares issued and outstanding at September 30, 2015 and December 31, 2014, respectively	$ 1,636	$ 1,562
Additional paid-in capital	626,340	505,446
Retained earnings (accumulated deficit)	43,692	(57,709)
Total stockholders' equity	671,668	449,299
Total liabilities and stockholders' equity	1,020,594	$ 911,619
Revolving Credit Facility [Member]
Current liabilities:
Borrowings under Credit Facility	$ 75,000