Consolidated Statements of Changes in Convertible Preferred Stock and Stockholders' Equity (Deficiency) - USD ($) $ in Thousands		Convertible Preferred Stock [Member]	Common Stock [Member]		Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Total
Balance as of January 1, 2013 (in shares) at Dec. 31, 2012		14,856,481	3,848,293
Balance as of January 1, 2013 at Dec. 31, 2012		$ 37,959	$ 4		$ 2,826		$ (40,278)	$ (37,448)
Exercise of warrants to purchase Series D convertible preferred stock (in shares)		225,660
Exercise of warrants to purchase Series D convertible preferred stock		$ 5,816
Allocated Share-based Compensation Expense					1,788			$ 1,788
Exercise of stock options (in shares)			105,021	[1]				105,021
Exercise of stock options					127			$ 127
Net loss							(7,475)	(7,475)
Balance (in shares) at Dec. 31, 2013		15,082,141	3,953,314
Balance at Dec. 31, 2013		$ 43,775	$ 4		4,741		(47,753)	$ (43,008)
Unrealized losses on derivative instruments
Unrealized loss on derivative instruments
Allocated Share-based Compensation Expense					4,664			$ 4,664
Exercise of stock options (in shares)			238,951	[1]				213,174
Exercise of stock options					381			$ 382
Net loss							(19,398)	(19,398)
Balance (in shares) at Dec. 31, 2014			24,685,604
Balance at Dec. 31, 2014			$ 25		162,478	$ (326)	(67,151)	95,026
Issuance of common stock upon initial public offering (net of issuance costs of $2,376) (in shares)			5,300,436
Issuance of common stock upon initial public offering (net of issuance costs of $2,376)			$ 5		106,066			106,071
Conversion of preferred stock to common stock upon initial public offering (in shares)		(15,082,141)	15,082,141
Conversion of preferred stock to common stock upon initial public offering		$ (43,775)	$ 15		43,760			43,775
Conversion of warrants to purchase preferred stock into warrants to purchase common stock					2,866			2,866
Exercise of warrants to purchase common stock (in shares)	[1]		107,217
Exercise of restricted stock units (in shares)	[1]		3,545
Unrealized losses on derivative instruments						(326)		(326)
Unrealized loss on derivative instruments						(326)		(326)
Allocated Share-based Compensation Expense					7,794			$ 7,794
Exercise of stock options (in shares)			1,350,162					1,334,351
Exercise of stock options					2,054			$ 2,055
Net loss							(21,283)	(21,283)
Balance (in shares) at Dec. 31, 2015			26,069,154
Balance at Dec. 31, 2015			$ 26		$ 172,326	(331)	$ (88,434)	83,587
Unrealized losses on derivative instruments						(5)		(5)
Exercise of restricted stock units (in shares)			33,388
Unrealized loss on derivative instruments						$ (5)		$ (5)

[1] Represents an amount lower than $1.