Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 46,293	$ 63,474
Short-term investments	180,750	148,703
Accounts receivable, net	6,410	5,932
Inventories	12,451	15,206
Receivable from collaboration	263	428
Assets held for sale	2,000
Prepaid and other current assets	6,213	6,288
Total current assets	254,380	240,031
Property, plant and equipment, net	3,297	9,206
Long-term investments		17,527
Restricted cash	460	460
Total assets	258,137	267,224
Current liabilities:
Accounts payable	3,515	3,732
Accrued expenses	20,338	28,916
Deferred revenues	9,104	6,346
Total current liabilities	32,957	38,994
Long-term liabilities:
Deferred revenues	50,350	45,196
Other long-term liabilities	2,033	2,438
Total liabilities	85,340	86,628
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; 21,506,754 and 21,306,413 shares issued and outstanding at December 31, 2012 and 2011, respectively	215	213
Additional paid-in capital	632,487	625,133
Accumulated other comprehensive loss	(3,247)	(4,842)
Accumulated deficit	(456,658)	(439,908)
Total stockholders' equity	172,797	180,596
Total liabilities and stockholders' equity	$ 258,137	$ 267,224