CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 31,609	$ 28,390
Short-term investments	43,940	43,967
Accounts receivable, net	12,015	13,993
Prepaid expenses and other current assets	1,303	1,322
Total current assets	88,867	87,672
Property and equipment, net	423	461
Goodwill	14,240	14,240
Intangible assets, net	3,181	3,454
Other assets	1,114	1,072
Total assets	107,825	106,899
Current liabilities:
Accounts payable	1,097	860
Accrued compensation	3,233	2,157
Other accrued liabilities	2,961	3,359
Short-term deferred revenue	2,985	3,323
Total current liabilities	10,276	9,699
Long-term deferred revenue	64	50
Other long-term liabilities	1,813	1,754
Total Liabilities	12,153	11,503
Commitments and contingencies (Note 4)
Stockholders' equity:
Common stock; par value $0.0001, 150,000,000 shares authorized; 54,651,443 issued and 53,458,845 outstanding at March 31, 2014; 54,474,594 issued and 53,281,996 outstanding at December 31, 2013	5	5
Additional paid-in capital	258,972	258,291
Treasury stock	(5,036)	(5,036)
Accumulated other comprehensive loss	(1,797)	(1,874)
Accumulated deficit	(156,472)	(155,990)
Total stockholders' equity	95,672	95,396
Total liabilities and stockholders' equity	$ 107,825	$ 106,899