XML 1051 R53.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Accrued Expenses - Schedule of Accrued Expenses (Details) - USD ($)
$ in Thousands
Sep. 30, 2019
Dec. 31, 2018
Dec. 31, 2017
Payables And Accruals [Abstract]      
Compensation, excluding taxes $ 3,274 $ 1,785 $ 1,124
Clinical trial expenses 2,590 4,530 869
Interest payable 33 402  
Other 640 1,247 985
Total accrued expenses $ 6,537 $ 7,964 $ 3,408