Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
CURRENT ASSETS:
Cash and cash equivalents	$ 192,538	$ 107,343
Short-term investments	166,993	153,749
Restricted cash	52	68
Accounts receivable, net of allowance of $936 and $ 1,784 as of December 31, 2017 and 2016, respectively	75,535	62,571
Inventory	617	590
Prepaid expenses and other current assets	14,894	7,922
Total current assets	450,629	332,243
Property and equipment, net	25,407	21,496
Goodwill	36,389	37,448
Acquired intangible assets, net	3,184	8,393
Severance pay fund	6,554	5,070
Restricted cash	2,284	1,884
Deferred tax assets	2,022	1,220
Other assets	1,593	1,065
TOTAL ASSETS	528,062	408,819
CURRENT LIABILITIES:
Accounts payable	5,869	5,529
Accrued compensation and benefits	22,913	20,840
Accrued and other current liabilities	11,417	7,683
Deferred revenue	126,174	104,042
Total current liabilities	166,373	138,094
Other liabilities	6,253	6,637
Deferred revenue	33,081	26,429
Accrued severance pay	7,238	5,696
TOTAL LIABILITIES	212,945	176,856
Commitments and Contingencies (Note 9)
STOCKHOLDERS' EQUITY:
Preferred stock, $0.0001 par value - 5,000,000 shares authorized, no shares issued and outstanding as of December 31, 2017 and 2016, respectively	0	0
Common stock, $0.0001 par value - 145,000,000 shares authorized, 34,233,888 and 33,088,990 shares issued and outstanding as of December 31, 2017 and 2016, respectively	3	3
Additional paid-in capital	572,106	510,257
Accumulated deficit	(256,537)	(276,819)
Accumulated other comprehensive loss	(455)	(1,478)
TOTAL STOCKHOLDERS' EQUITY	315,117	231,963
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 528,062	$ 408,819