XML 44 R31.htm IDEA: XBRL DOCUMENT v3.21.2
Balance Sheets Components - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($)
$ in Thousands
Jun. 30, 2021
Dec. 31, 2020
Prepaid Expense And Other Assets Current [Abstract]    
Advance to suppliers $ 339 $ 853
Prepaid expenses 1,700 1,074
Other current assets 805 722
Total prepaid expenses and other current assets $ 2,844 $ 2,649