Consolidated Statements of Changes in Convertible Preferred Stock and Stockholders' Equity (Deficiency) (Unaudited) - 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, 2014 (in shares) at Dec. 31, 2013		15,082,141	3,953,314
Balance as of January 1, 2014 at Dec. 31, 2013		$ 43,775	$ 4	$ 4,741		$ (47,753)	$ (43,008)
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)			107,217
Exercise of warrants to purchase common stock	[1]
Stock-based compensation expense				4,664			4,664
Exercise of stock options (in shares)			238,951
Exercise of stock options				381			382
Exercise of restricted stock units (in shares)			3,545
Exercise of restricted stock units	[1]
Unrealized gains on derivative instruments					$ (326)
Net loss						$ (19,398)	(19,398)
Balance as of December 31, 2014 (in shares) at Dec. 31, 2014			24,685,604
Balance as of December 31, 2014 at Dec. 31, 2014			$ 25	162,478	(326)	(67,151)	95,026
Stock-based compensation expense				3,647			$ 3,647
Exercise of stock options (in shares)			218,437				202,771
Exercise of stock options				619			$ 619
Exercise of restricted stock units (in shares)			4,080
Exercise of restricted stock units
Unrealized gains on derivative instruments					936		936
Net loss						(18,992)	(18,992)
Balance as of December 31, 2014 (in shares) at Jun. 30, 2015			24,908,121
Balance as of December 31, 2014 at Jun. 30, 2015			$ 25	$ 166,744	$ 610	$ (86,143)	$ 81,236

[1] Represents an amount lower than $1.