Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
CURRENT ASSETS:
Cash and cash equivalents	$ 214,274	$ 192,538
Short-term investments	164,535	166,993
Restricted cash	51	52
Accounts receivable, net of allowance of $1,121 and $936 as of March 31, 2018 and December 31, 2017, respectively	59,218	75,535
Deferred costs, current	4,452	0
Inventory	162	617
Prepaid expenses and other current assets	16,331	14,894
Total current assets	459,023	450,629
Property and equipment, net	23,693	25,407
Goodwill	36,389	36,389
Intangible assets, net	3,052	3,184
Severance pay fund	6,418	6,554
Restricted cash	2,332	2,284
Deferred tax assets	2,744	2,022
Other assets including non-current deferred cost	15,455	1,593
TOTAL ASSETS	549,106	528,062
CURRENT LIABILITIES:
Accounts payable	5,514	5,869
Accrued compensation and benefits	24,876	22,913
Accrued and other current liabilities	10,576	11,417
Deferred revenue, current	121,818	126,174
Total current liabilities	162,784	166,373
Other non-current liabilities	6,170	6,253
Deferred revenue	34,575	33,081
Long-term accrued severance pay	7,316	7,238
TOTAL LIABILITIES	210,845	212,945
Commitments and contingencies (See note 6)
STOCKHOLDERS' EQUITY:
Common stock, $0.0001 par value - 145,000,000 shares authorized, 34,733,955 and 34,233,888 shares issued and outstanding as of March 31, 2018 and December 31, 2017, respectively	3	3
Additional paid-in capital	586,365	572,106
Accumulated deficit	(246,845)	(256,537)
Accumulated other comprehensive loss	(1,262)	(455)
TOTAL STOCKHOLDERS' EQUITY	338,261	315,117
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 549,106	$ 528,062