Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 57,959	$ 32,869
Short-term marketable securities	68,251	67,605
Accounts receivable (net of allowance for doubtful accounts; 2012 - $1,171, 2011 - $1,206)	19,926	21,077
Prepaid expenses and other current assets	8,630	7,444
Total current assets	154,766	128,995
Long-term marketable securities	771
Property and equipment, net	11,799	9,443
Other assets	5,837	4,560
Total assets	173,173	142,998
Current liabilities:
Accounts payable	3,392	7,025
Accrued compensation	9,636	9,574
Accrued license fees	2,082	1,947
Accrued expenses and other current liabilities	8,122	5,501
Deferred revenues - current portion	800	1,849
Other current liabilities	93	243
Total current liabilities	24,125	26,139
Deferred revenues - long-term portion		211
Other liabilities	2,211	1,289
Commitments (Note 5)
Stockholders' equity:
Common stock	3	3
Additional paid-in capital	306,289	281,147
Accumulated other comprehensive income loss	16	(30)
Accumulated deficit	(159,471)	(165,761)
Total stockholders' equity	146,837	115,359
Total liabilities and stockholders' equity	$ 173,173	$ 142,998