v3.20.1
Summary of Significant Accounting Policies; Prior Period Reclassification - Summary of Financial Assets and Liabilities Measured at Fair Value (Detail) - Recurring [Member] - Level 3 [Member] - Derivative Liability [Member]
$ in Thousands
12 Months Ended
Dec. 31, 2019
USD ($)
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]  
Initial recognition of conversion features and warrants $ 7,954
Change in fair value of derivative liability (6,233)
Balance, December 31, 2019 $ 1,721