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Fair Value Measurements - Assets and Liabilities Carried at Fair Value Measured on Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($)
$ in Thousands
Dec. 31, 2019
Dec. 31, 2018
Assets:    
Cash equivalents $ 19,976 $ 43,194
Total cash equivalents 19,976 43,194
Quoted Prices in Active Markets (Level 1) [Member]    
Assets:    
Cash equivalents 19,976 43,194
Total cash equivalents 19,976 43,194
Significant Other Observable Inputs (Level 2) [Member]    
Assets:    
Cash equivalents 0 0
Total cash equivalents 0 0
Significant Unobservable Inputs (Level 3) [Member]    
Assets:    
Cash equivalents 0 0
Total cash equivalents $ 0 $ 0