XML 36 R25.htm IDEA: XBRL DOCUMENT v3.19.1
Balance Sheet Components - Prepaid Expenses and Other Current Assets (Detail) - USD ($)
$ in Thousands
Mar. 31, 2019
Dec. 31, 2018
Prepaid Expense And Other Assets [Abstract]    
Preclinical and clinical $ 908 $ 416
Lease receivable 969 606
Other 14 16
Total $ 1,891 $ 1,038