Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
CURRENT ASSETS:
Cash and cash equivalents	$ 209,194	$ 192,538
Short-term investments	185,278	166,993
Restricted cash	30	52
Accounts receivable, net of allowance of $1,160 and $936 as of June 30, 2018 and December 31, 2017, respectively	70,307	75,535
Deferred costs, current	5,765	0
Inventory	196	617
Prepaid expenses and other current assets	12,975	14,894
Total current assets	483,745	450,629
Property and equipment, net	22,740	25,407
Goodwill	36,389	36,389
Intangible assets, net	2,920	3,184
Severance pay fund	5,950	6,554
Restricted cash	2,334	2,284
Deferred tax assets	1,017	2,022
Other assets including non-current deferred costs	19,393	1,593
TOTAL ASSETS	574,488	528,062
CURRENT LIABILITIES:
Accounts payable	5,139	5,869
Income taxes	10,015	319
Accrued compensation and benefits	22,668	22,913
Accrued and other current liabilities	13,970	11,098
Deferred revenue, current	128,519	126,174
Total current liabilities	180,311	166,373
Long-term accrued severance pay	7,346	7,238
Other non-current liabilities	12,264	6,253
Deferred revenue	46,132	33,081
TOTAL LIABILITIES	246,053	212,945
Commitments and contingencies (See note 6)
STOCKHOLDERS' EQUITY:
Common stock, $0.0001 par value - 145,000,000 shares authorized, 34,956,475 and 34,233,888 shares issued and outstanding as of June 30, 2018 and December 31, 2017, respectively	3	3
Additional paid-in capital	601,298	572,106
Accumulated deficit	(269,904)	(256,537)
Accumulated other comprehensive loss	(2,962)	(455)
TOTAL STOCKHOLDERS' EQUITY	328,435	315,117
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 574,488	$ 528,062