Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 265,814	$ 224,057
Marketable securities-available-for-sale	4,365	4,361
Accounts receivable, net	28,041	70,951
Inventory	189	278
Prepaid expenses and other current assets	10,704	9,867
Total current assets	309,113	309,514
Inventory	9,141	8,475
Property and equipment, net	6,485	6,348
Intangible and other assets, net	5,543	6,082
Total assets	330,282	330,419
Current liabilities:
Accounts payable	15,515	13,961
Accrued compensation	11,836	22,899
Interest payable	9,500	4,750
Accrued and other current liabilities	31,878	28,385
Deferred revenue-Collaborative agreements	52,554	66,079
Total current liabilities	121,283	136,074
Convertible senior notes	328,354	322,043
Convertible subordinated note	9,159	9,033
Deferred revenue-Collaborative agreements	35,012	38,226
Total liabilities	493,808	505,376
Stockholders'deficit:
Preferred stock, $0.001 par value; 5,000,000 shares authorized; none issued or outstanding as of March 31, 2013 and December 31, 2013
Common stock, $0.001 par value; 400,000,000 shares authorized; 135,529,786 and 133,462,185 shares issued and outstanding as of March 31, 2013 and December 31, 2012, respectively	136	133
Additional paid-in capital	1,503,898	1,476,922
Accumulated other comprehensive gain	1,999	1,878
Accumulated deficit	(1,669,559)	(1,653,890)
Total stockholders' deficit	(163,526)	(174,957)
Total liabilities and stockholders'deficit	$ 330,282	$ 330,419