Quarterly report pursuant to Section 13 or 15(d)

Financial Instruments - Schedule of Cash and Available-For-Sale Securities' Cost, Gross Unrealized Losses and Fair Value by Significant Investment Category (Detail)

v3.20.1
Financial Instruments - Schedule of Cash and Available-For-Sale Securities' Cost, Gross Unrealized Losses and Fair Value by Significant Investment Category (Detail) - USD ($)
$ in Thousands
Mar. 31, 2020
Dec. 31, 2019
Schedule of Available-for-sale Securities [Line Items]    
Cash and cash equivalents $ 49,165 $ 44,065
Total Cash and Debt Securities 49,165 44,065
Total Fair Value, Cash and Debt Securities 49,165 44,065
Cash [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Cash and cash equivalents 35,749 23,710
Fair Value, Cash 35,749 23,710
Level 1 [Member] | Money Market Funds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Cash and cash equivalents 13,416 20,355
Cash and cash equivalents gross before unrealized losses 13,416 20,355
Fair Value, Cash $ 13,416 $ 20,355