Accrued Expenses And Other Liabilities - Schedule of Accrued Expenses and Other Liabilities (Details) - USD ($)	Jun. 30, 2018	Dec. 31, 2017
Payables And Accruals [Abstract]
Accrued compensation and benefits	$ 1,526,964	$ 1,435,015
Accrued professional fees	388,267	1,119,959
Accrued research and development expenses	326,401	182,500
Accrued unvested common stock subject to repurchase	116,801	122,551
Accrued expenses	$ 2,358,433	$ 2,860,025