Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 56,689	$ 48,315
Short-term investments	79,868	65,493
Trade receivables (net of allowance for doubtful accounts of $ 433 and $ 372 at December 31, 2017 and at December 31, 2016, respectively)	75,596	53,861
Prepaid expenses and other current assets	7,130	3,650
Total current assets	219,283	171,319
Long-term assets:
Other assets	973	609
Property and equipment, net	11,896	9,910
Total long-term assets	12,869	10,519
Total assets	232,152	181,838
Current liabilities:
Trade payables	635	1,288
Accrued expenses and other short term liabilities	42,453	28,479
Deferred revenues	73,891	58,478
Total current liabilities	116,979	88,245
Long-term liabilities:
Deferred revenues	7,034	3,562
Other liabilities	6,561	7,292
Total long-term liabilities	13,595	10,854
Stockholders’ equity:
Common stock of $ 0.001 par value—Authorized: 200,000,000 shares at December 31, 2017 and 2016; Issued and outstanding: 28,146,162 shares at December 31, 2017 and 26,821,762 shares at December 31, 2016	28	27
Accumulated other comprehensive income (loss)	136	(479)
Additional paid-in capital	223,868	189,335
Accumulated deficit	(122,454)	(106,144)
Total stockholders’ equity	101,578	82,739
Total liabilities and stockholders’ equity	$ 232,152	$ 181,838