XML 22 R30.htm IDEA: XBRL DOCUMENT v3.19.3
Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Detail) - USD ($)
$ in Thousands
Sep. 30, 2019
Dec. 31, 2018
Payables And Accruals [Abstract]    
Accrued employee compensation and benefits $ 2,259 $ 1,599
Accrued external research and development expense 2,618 1,799
Accrued external manufacturing costs 588 1,015
Other 1,073 1,064
Total $ 6,538 $ 5,477