Accrued Expense - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounts Payable and Accrued Liabilities [Line Items]
Accrued expense	$ 969	$ 883
Accrued Vacation And Bonus	400	400
Accrued Laboratory Expense	200
Accrued Clinical And Preclinical	200	300
Accrued License Maintenance Fee	100	100
Other Accrued Liabilities	$ 100	$ 100