Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 258,202	$ 224,057
Marketable securities-available-for-sale	19,251	4,361
Accounts receivable, net	27,522	70,951
Inventory	133	278
Prepaid expenses and other current assets	8,261	9,867
Total current assets	313,369	309,514
Inventory	11,410	8,475
Property and equipment, net	6,236	6,348
Intangible and other assets, net	3,204	6,082
Total assets	334,219	330,419
Current liabilities:
Accounts payable	13,471	13,961
Accrued compensation	14,327	22,899
Interest payable	3,044	4,750
Accrued and other current liabilities	33,087	28,385
Deferred revenue-Collaborative agreements	39,029	66,079
Total current liabilities	102,958	136,074
Convertible senior notes	214,530	322,043
Convertible subordinated note	9,287	9,033
Other liabilities	3,433
Deferred revenue-Collaborative agreements	31,797	38,226
Total liabilities	362,005	505,376
Stockholders' deficit:
Preferred stock, $0.001 par value; 5,000,000 shares authorized; none issued or outstanding as of June 30, 2013 and December 31, 2012
Common stock, $0.001 par value; 400,000,000 shares authorized; 152,915,117 and 133,462,185 shares issued and outstanding as of June 30, 2013 and December 31, 2012, respectively	153	133
Additional paid-in capital	1,642,198	1,476,922
Accumulated other comprehensive gain	1,993	1,878
Accumulated deficit	(1,672,130)	(1,653,890)
Total stockholders' deficit	(27,786)	(174,957)
Total liabilities and stockholders' deficit	$ 334,219	$ 330,419