Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 57,014	$ 32,869
Short-term marketable securities	55,570	67,605
Accounts receivable (net of allowance for doubtful accounts; 2012 - $1,145, 2011 - $1,206)	21,699	21,077
Prepaid expenses and other current assets	8,206	7,444
Total current assets	142,489	128,995
Long-term marketable securities	1,291
Property and equipment, net	10,276	9,443
Other assets	4,923	4,560
Total assets	158,979	142,998
Current liabilities:
Accounts payable	3,489	7,025
Accrued compensation	9,881	9,574
Accrued license fees	1,889	1,947
Accrued expenses and other current liabilities	5,765	5,501
Deferred revenues - current portion	1,403	1,407
Other current liabilities	93	685
Total current liabilities	22,520	26,139
Deferred revenues - long-term portion		211
Other liabilities	2,205	1,289
Commitments (Note 5)
Stockholders' equity:
Common stock	3	3
Additional paid-in capital	297,437	281,147
Accumulated other comprehensive income loss	(2)	(30)
Accumulated deficit	(163,184)	(165,761)
Total stockholders' equity	134,254	115,359
Total liabilities and stockholders' equity	$ 158,979	$ 142,998