Accrued Liabilities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accrued Liabilities
Payroll and related costs	$ 280,235	$ 539,063
Research and development	184,120	322,842
Professional fees	151,812	75,934
Legal fees	34,072	81,550
Other	11,182	27,309
Total accrued expenses	661,421	$ 1,046,698
Severance costs	1,300,000
Severance costs included in payroll and related costs	$ 36,000