Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Summary of Cash and Cash Equivalents (Detail)

v3.20.4
Fair Value Measurements - Summary of Cash and Cash Equivalents (Detail) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Cash, amortized cost and estimated fair value $ 473 $ 949
Cash and cash equivalents, amortized cost and estimated fair value 35,853 16,664
Restricted cash, amortized cost and estimated fair value 50 50
Money market securities [Member]    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Cash equivalents, amortized cost and estimated fair value 35,380 15,715
Restricted cash, amortized cost and estimated fair value $ 50 $ 50