Accrued Expenses And Other Liabilities - Schedule of Accrued Expenses and Other Liabilities (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Payables And Accruals [Abstract]
Accrued professional fees	$ 1,156,451	$ 1,119,959
Accrued compensation and benefits	844,451	1,435,015
Accrued unvested common stock subject to repurchase	107,135	122,551
Accrued research and development expenses	150,000	182,500
Accrued expenses	$ 2,258,037	$ 2,860,025