Nature of the Business (Details) (USD $)	0 Months Ended	12 Months Ended	0 Months Ended
	Oct. 01, 2014	Dec. 31, 2014	Nov. 10, 2014	Dec. 31, 2013
Note 1 - Nature of the Business (Details) [Line Items]
Stockholders' Equity Note, Stock Split, Conversion Ratio	4.86
Stockholders' Equity Note, Reverse Stock Split		On October 1, 2014, the Company effected a 1 for 4.86 reverse share split of its common and Series A, B and E redeemable convertible preferred shares. At the time of the consolidation, there were no outstanding Series C and D preferred shares and therefore such series were not included in the consolidation. Accordingly, (i) every 4.86 common shares were combined into one common share, (ii) every 4.86 redeemable Series A, B and E convertible preferred shares were combined into one redeemable convertible preferred share, (iii) the number of common shares into which each outstanding subscription right was exchangeable into common shares were proportionately decreased on a 1 for 4.86 basis, (iv) the number of common shares into which each outstanding option to purchase common shares was exercisable were proportionately decreased on a 1 for 4.86 basis, and (v) the exercise price for each such outstanding option to purchase common shares was proportionately increased on a 1 for 4.86 basis. All of the share numbers, share prices, and exercise prices in these financial statements have been adjusted, on a retroactive basis, to reflect this 1 for 4.86 reverse share split.
Preferred Stock, Shares Outstanding			0
Common shares, Outstanding		14,181,333	14,181,333	1,344,627
Converted from Convertible Preferred Shares [Member]
Note 1 - Nature of the Business (Details) [Line Items]
Subscribed common stock issued			7,725,924
Converted from Subscription Rights [Member]
Note 1 - Nature of the Business (Details) [Line Items]
Subscribed common stock issued			10,201
IPO [Member]
Note 1 - Nature of the Business (Details) [Line Items]
Issuance of common shares, net of issuance costs (in Shares)			4,600,000
Share Price (in Dollars per share)			9.00
Common Stock [Member]
Note 1 - Nature of the Business (Details) [Line Items]
Issuance of common shares, net of issuance costs (in Shares)		5,095,000
Subscription rights converted into common shares			10,201
Common Stock [Member] | Private Placement [Member] | Genentech Affiliate [Member]
Note 1 - Nature of the Business (Details) [Line Items]
Issuance of common shares, net of issuance costs (in Shares)			495,000
Share Price (in Dollars per share)			9.00
Common Stock [Member] | Reverse Stock Split [Member]
Note 1 - Nature of the Business (Details) [Line Items]
Stockholders' Equity Note, Stock Split, Conversion Ratio	4.86
Series A Preferred Stock [Member]
Note 1 - Nature of the Business (Details) [Line Items]
Stockholders' Equity Note, Stock Split, Conversion Ratio		1
Preferred Stock, Shares Outstanding		0		1,151,468
Series A Preferred Stock [Member] | Preferred Stock [Member] | Reverse Stock Split [Member]
Note 1 - Nature of the Business (Details) [Line Items]
Stockholders' Equity Note, Stock Split, Conversion Ratio	4.86
Series B Preferred Stock [Member]
Note 1 - Nature of the Business (Details) [Line Items]
Stockholders' Equity Note, Stock Split, Conversion Ratio		1
Preferred Stock, Shares Outstanding		0		994,885
Series B Preferred Stock [Member] | Preferred Stock [Member] | Reverse Stock Split [Member]
Note 1 - Nature of the Business (Details) [Line Items]
Stockholders' Equity Note, Stock Split, Conversion Ratio	4.86
Series E Preferred Stock [Member]
Note 1 - Nature of the Business (Details) [Line Items]
Stockholders' Equity Note, Stock Split, Conversion Ratio		1
Preferred Stock, Shares Outstanding		0		4,322,126
Series E Preferred Stock [Member] | Preferred Stock [Member] | Reverse Stock Split [Member]
Note 1 - Nature of the Business (Details) [Line Items]
Stockholders' Equity Note, Stock Split, Conversion Ratio	4.86
Series C Preferred Stock [Member]
Note 1 - Nature of the Business (Details) [Line Items]
Preferred Stock, Shares Outstanding		0		0
Series D Preferred Stock [Member]
Note 1 - Nature of the Business (Details) [Line Items]
Preferred Stock, Shares Outstanding		0		0