Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 63,474	$ 112,646
Short-term investments	148,703	147,619
Accounts receivable, net	5,932	5,785
Inventories	15,206	16,344
Receivable from collaboration	428	441
Prepaid and other current assets	6,288	7,949
Total current assets	240,031	290,784
Property, plant and equipment, net	9,206	11,235
Long-term investments	17,527	33,597
Restricted cash	460	460
Total assets	267,224	336,076
Current liabilities:
Accounts payable	3,732	4,553
Accrued expenses	28,916	25,555
Deferred revenues	6,346	6,603
Total current liabilities	38,994	36,711
Long-term liabilities:
Deferred revenues	45,196	51,292
Other long-term liabilities	2,438	2,787
Total liabilities	86,628	90,790
Commitments and contingencies (Notes M & N)
Stockholders' equity:
Preferred stock, par value $0.01 per share, 2,000,000 shares authorized; none issued
Common stock, par value $0.01 per share, 58,750,000 shares authorized; 21,306,413 and 21,137,428 shares issued and outstanding at December 31, 2011 and 2010, respectively	213	211
Additional paid-in capital	625,133	614,942
Accumulated other comprehensive loss	(4,842)	(7,028)
Accumulated deficit	(439,908)	(362,839)
Total stockholders' equity	180,596	245,286
Total liabilities and stockholders' equity	$ 267,224	$ 336,076