Capitalization Narrative (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended					0 Months Ended							0 Months Ended		9 Months Ended	0 Months Ended
	Apr. 07, 2014	Sep. 30, 2014	Apr. 01, 2014	Mar. 14, 2014	Dec. 31, 2013	Apr. 07, 2014 Common Class A	Dec. 31, 2013 Common Class A	Apr. 07, 2014 Common Stock	Dec. 31, 2013 Common Class B	Dec. 31, 2013 Convertible Preferred Stock	Sep. 30, 2014 Preferred Stock	Apr. 07, 2014 Preferred Stock	Apr. 07, 2014 Common Stock	Mar. 18, 2014 Common Stock	Sep. 30, 2014 Common Stock	Jun. 23, 2014 Common Stock	Apr. 07, 2014 Common Stock	Apr. 07, 2014 Conversion of convertible preferred stock	Dec. 31, 2013 Conversion of convertible preferred stock	Apr. 01, 2014 Series C	Dec. 31, 2013 Series C
Class of Stock [Line Items]
Common Stock, Shares Authorized		500,000,000		80,608,856	73,380,126		32,500,000	500,000,000	4,190,063
Temporary Equity, Shares Authorized										29,691,524
Initial Public Offering, Shares sold During IPO													6,432,445		6,432,000
Initial Public Offering, Shares sold During IPO, Over-Allotment Option													1,015,649
Initial Public Offering, Shares Sold by Existing Stockholders													1,354,199
Share Price			$ 15.00										$ 15.00
Proceeds from Issuance Initial Public Offering	$ 86.2
Stock Issued During Period, Shares, Conversion of Convertible Securities						14,410,238									14,696,000	9,671	286,055
Stockholders' Equity Note, Stock Split, Conversion Ratio						0.5								0.5
Conversion of Stock, Shares Converted						1
Class of Warrant or Right, Outstanding																				845,867	845,867
Class of Warrant or Right, Number of Securities Called by Warrants or Rights																12,587	12,587	25,174	25,174
Preferred Stock, Shares Authorized											10,000,000	10,000,000
Deferred Offering Costs	$ 3.5