Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 18,005	$ 32,869
Short-term marketable securities	81,060	67,605
Accounts receivable (net of allowance for doubtful accounts; 2012-$1,133, 2011-$1,206)	22,253	21,077
Prepaid expenses and other current assets	8,891	7,444
Total current assets	130,209	128,995
Property and equipment, net	14,104	9,443
Other assets	9,421	4,560
Total assets	153,734	142,998
Current liabilities:
Accounts payable	4,881	7,025
Accrued compensation	11,210	9,574
Accrued license fees	2,292	1,947
Accrued expenses and other current liabilities	6,340	5,501
Deferred revenues-current portion	374	1,407
Other current liabilities	243	685
Total current liabilities	25,340	26,139
Deferred revenues-long-term portion		211
Other liabilities	2,068	1,289
Commitments (Note 7)
Stockholders' equity:
Preferred stock, $0.0001 par value, 5,000,000 shares authorized, none issued and outstanding at December 31, 2012 and 2011
Common stock, $0.0001 par value; 100,000,000 shares authorized, 30,937,889 and 29,761,022 shares issued and 29,953,815 and 29,761,022 shares outstanding at December 31, 2012 and 2011, respectively	3	3
Additional paid-in capital	313,915	281,147
Accumulated other comprehensive income (loss), net	15	(30)
Accumulated deficit	(157,512)	(165,761)
Treasury stock, at cost, 984,084 shares at December 31, 2012	(30,095)
Total stockholders' equity	126,326	115,359
Total liabilities and stockholders' equity	$ 153,734	$ 142,998