Organization and Basis of Presentation (Details) (USD $)	0 Months Ended					6 Months Ended	119 Months Ended
	May 22, 2013	May 22, 2013	May 16, 2013	Jan. 31, 2013	Jan. 29, 2013	Jun. 30, 2013	Jun. 30, 2013
Organization and Basis of Presentation
Number of shares issued in initial public offering or in secondary public offering			4,137,931	3,317,644
Share price (in dollars per share)	$ 14.50		$ 14.50	$ 10.00	$ 10.00
Number of shares issued pursuant to an option granted to the underwriters to cover over-allotments	620,689				497,647
Aggregate gross proceeds from initial public offering				$ 38,200,000
Aggregate gross proceeds from secondary public offering		69,000,000
Proceeds from secondary public offering net of underwriting fees and offering expenses		64,500,000				97,708,506	101,550,788
Net proceeds received after underwriting fees and offering expenses				32,300,000
Number of shares of common stock issued upon conversion of debt				166,769
Principal amount of convertible debt converted				1,400,000
Compensation expense related to certain bonuses and salary increases payable upon continued employment and the occurrence of a specified financing				1,500,000
Stock-based compensation expense for awards that fully vested upon consummation of IPO (in dollars)				$ 1,400,000