Share Capital (Details) - USD ($) $ / shares in Units, $ in Thousands				1 Months Ended	12 Months Ended
	Sep. 13, 2016	Nov. 10, 2014	Jun. 25, 2014	Jan. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Proceeds from net of underwriting discounts and commissions Before offering expenses					$ 23,832		$ 42,644
Preferred Stock, Shares Outstanding		0
Number of Options Exercisable					1,292,012
Options Exercisable Weighted Average Remaining Contractual Life in Years					4 years 10 months 10 days
Aggregate fair value of options vested					$ 3,220	$ 999	$ 722
Unrecognized stock-based compensation cost					$ 3,975
Unrecognized stock-based compensation expected to be recognized over a period					2 years 4 months 10 days
Amended And Restated Stock Option Plan [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options exercise term					10 years
Options vesting period					4 years
Two Thousand Fourteen Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Options, Granted					65,132
Two Thousand Fourteen Plan [Member] | Subsequent Event [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance				500,000
Two Thousand Fourteen Plan [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options exercise term			10 years
Options vesting period			4 years
Converted from Convertible Preferred Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock issued upon conversion of preferred stock		7,725,924
Converted from Subscription Rights [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock issued upon conversion of subscription rights		10,201
Series A Preferred Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Convertible Preferred Stock, Shares Issued upon Conversion					converted into common shares on a 1:1 basis
Series B Preferred Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Convertible Preferred Stock, Shares Issued upon Conversion					converted into common shares on a 1:1 basis
Series E Preferred Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Convertible Preferred Stock, Shares Issued upon Conversion					converted into common shares on a 1:1.2 basis
IPO [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common shares, net of issuance costs (in Shares)		4,600,000
Common share price (in Dollars per share)		$ 9.00
Proceeds from net of underwriting discounts and commissions Before offering expenses		$ 38,500
Concurrent Private Placement [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Proceeds from net of underwriting discounts and commissions Before offering expenses		$ 4,100
Underwritten Public Offering [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common shares, net of issuance costs (in Shares)	3,450,000
Common share price (in Dollars per share)	$ 7.50
Proceeds from net of underwriting discounts and commissions Before offering expenses	$ 24,300
Common Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common shares, net of issuance costs (in Shares)					3,450,000		5,095,000
Common stock issued upon conversion of preferred stock							7,725,924
Common stock issued upon conversion of subscription rights		10,201
Common Stock [Member] | Private Placement [Member] | Genentech Affiliate [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common shares, net of issuance costs (in Shares)		495,000
Common share price (in Dollars per share)		$ 9.00