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Assets Measured at Fair Value on Recurring Basis (Detail)
$ in Thousands
Dec. 31, 2019
USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]  
Short-term investments - trading securities $ 2,010
Fair Value, Inputs, Level 2  
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]  
Short-term investments - trading securities $ 2,010