CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 229,252	$ 171,552
Marketable securities, current	325,540	474,791
Accounts receivable, net	25,448
Inventory	4,274
Receivable from collaboration partners	54,069	57,941
Prepaid expenses and other current assets	34,625	27,565
Total current assets	673,208	731,849
Marketable securities, non-current	18,239	22,102
Property and equipment, net	48,673	19,734
Intangible assets, net	434,690	438,800
Goodwill	193,675	193,675
Other assets	7,878	5,564
Total assets	1,376,363	1,411,724
Current liabilities:
Accounts payable and accrued liabilities	37,072	31,228
Accrued clinical trials and related expenses	49,747	39,574
Accrued compensation	21,352	15,639
Deferred revenue	5,129
Liability for contingent consideration, current		22,174
Lease termination exit costs, current		3,177
Other current liabilities	1,475
Total current liabilities	114,775	111,792
Convertible senior notes due 2016	171,395	162,893
Liability for contingent consideration, non-current	146,225	137,816
Deferred tax liability	64,023	149,413
Other liabilities	49,302	26,397
Commitments and contingencies (Note 11)
Stockholders' equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized; none issued and outstanding
Common stock, $0.001 par value; 200,000,000 shares authorized; 66,878,939 and 63,928,082 shares issued and outstanding as of September 30, 2012 and December 31, 2011, respectively	67	64
Additional paid-in capital	1,440,013	1,289,080
Receivable from stock option exercises	(1,119)	(434)
Accumulated other comprehensive loss	(166)	(2,011)
Accumulated deficit	(608,152)	(463,286)
Total stockholders' equity	830,643	823,413
Total liabilities and stockholders' equity	$ 1,376,363	$ 1,411,724