Summary of Significant Accounting Policies - Additional Information (Details) (USD $)	3 Months Ended			9 Months Ended			0 Months Ended
	Sep. 30, 2014	Mar. 25, 2014	Sep. 30, 2013	Sep. 30, 2014 Segment	Sep. 30, 2013	Dec. 31, 2013	Mar. 25, 2014 IPO	Mar. 25, 2014 Overallotment option granted to underwriters
Summary Of Significant Accounting Policies [Line Items]
Common stock, shares issued	20,300,243			20,300,243		1,383,345	6,762,000
Common stock sold								879,647
Sale of stock, price per share							$ 17.00
Proceeds from issuance of initial public offering							$ 104,364,560
Convertible redeemable preferred stock converted into common stock	0	12,115,183		0			12,115,183
Common stock, shares authorized	175,000,000	175,000,000		175,000,000		14,700,000
Preferred stock, shares authorized	25,000,000	25,000,000		25,000,000		0
Accretion on preferred stock		86,899,555	2,748,232	86,899,555	52,861,367
Number of operating segments				1
Short-term investments, maturities				three months or less
Significant uncertain tax positions	0			0		0
Revenue				0
Expected dividend yield				0.00%
Property, plant and equipment, Useful life				3 years
Depreciation expense	$ 13,193		$ 26	$ 33,285	$ 26