CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ DEFICIT - 6 months ended Jun. 30, 2016 - USD ($) $ in Thousands	Common stock	Additional paid-In capital Series D redeemable convertible preferred stock	Additional paid-In capital Series E redeemable convertible preferred stock	Additional paid-In capital	Accumulated deficit	Accumulated comprehensive loss	Series A redeemable convertible preferred stock	Series B redeemable convertible preferred stock	Series C redeemable convertible preferred stock	Series D redeemable convertible preferred stock	Series SRN redeemable convertible preferred stock	Series E redeemable convertible preferred stock	Total
Balance at Dec. 31, 2015							$ 3,644	$ 21,448	$ 20,178	$ 42,902	$ 12,082	$ 37,228	$ 137,482
Balance (in shares) at Dec. 31, 2015							2,589,868	7,437,325	5,000,002	8,099,994	2,111,109	8,888,888
Increase (Decrease) in Temporary Equity [Roll Forward]
Accretion of preferred stock to redemption value							$ 75	$ 449	$ 446	$ 1,131	$ 913	$ 1,552	4,566
Conversion of convertible stock upon listing							$ (3,719)	$ (21,897)	$ (20,624)	$ (44,033)	$ (12,995)	$ (38,780)
Conversion of convertible stock upon listing (in shares)							(2,589,868)	(7,437,325)	(5,000,002)	(8,099,994)	(2,111,109)	(8,888,888)
Balance at Jun. 30, 2016											$ 5,000
Balance (in shares) at Jun. 30, 2016							0	0	0	0	0	0
Balance at Dec. 31, 2015				$ 1	$ (111,508)	$ (4,986)							(116,493)
Balance (in shares) at Dec. 31, 2015	2,173,399
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted common stock				10									10
Vesting of restricted common stock (in shares)	3,791
Issuance of common stock upon exercise of options				48									48
Issuance of common stock upon exercise of options (in shares)	25,210
Exercise of common warrants (in shares)	567,306
Stock based compensation expense				649									649
Accretion of preferred stock to redemption value				(708)	(3,858)								(4,566)
Conversion of convertible stock upon listing	$ 1			142,047									142,048
Conversion of convertible securities upon listing (in shares)	10,126,118
Issuance of common stock, initial public offering net of issuance costs of $9,224	$ 5,000,000			60,776									60,776
Conversion of preferred stock warrants into warrants for the purchase of common stock		$ 189	$ 113							$ 189		$ 113
Currency translation adjustment						401							401
Net loss					(14,399)								(14,399)
Balance at Jun. 30, 2016	$ 1			$ 203,125	$ (129,765)	$ (4,585)							$ 68,776
Balance (in shares) at Jun. 30, 2016	17,895,824