Accrued Expenses - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Accounts Payable and Accrued Liabilities [Line Items]
Accrued expenses	$ 634	$ 969
Accrued Vacation And Bonus	300	400
Accrued Laboratory Expense		200
Accrued Clinical And Preclinical	200	200
Accrued License Maintenance Fee		100
Other Accrued Liabilities	$ 100	$ 100