Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 44,907	$ 50,239
Marketable securities	156,878	196,474
Trade and other receivables, net	13,005	13,974
Prepaid expenses and other current assets	13,663	12,303
Total current assets	228,453	272,990
Property and equipment, net	31,531	30,485
Goodwill	172,087	172,087
Intangible assets, net	27,132	30,174
Deferred tax assets, net	84,861	77,363
Other non-current assets	9,639	9,710
Total assets	553,703	592,809
Current liabilities:
Accounts payable	11,212	24,747
Accrued expenses and other liabilities	83,853	76,226
Deferred revenue	185,605	166,403
Total current liabilities	280,670	267,376
Other non-current liabilities	7,613	7,367
Total liabilities	$ 288,283	$ 274,743
Commitments and contingencies
Stockholders’ equity:
Common stock, $0.001 par value, 300,000,000 authorized at March 31, 2016 and December 31, 2015; 98,450,128 and 95,877,947 shares issued and 94,029,796 and 95,832,238 outstanding at March 31, 2016 and December 31, 2015, respectively	$ 98	$ 96
Preferred stock, $0.001 par value, 10,000,000 shares authorized and no shares issued and outstanding at March 31, 2016 and December 31, 2015	0	0
Treasury stock, at cost; 3,885,695 shares and no shares held at March 31, 2016 and December 31, 2015, respectively	(38,048)	0
Additional paid-in capital	528,742	532,388
Accumulated other comprehensive loss	(91)	(361)
Accumulated deficit	(225,281)	(214,057)
Total stockholders’ equity	265,420	318,066
Total liabilities and stockholders’ equity	$ 553,703	$ 592,809