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Fair Value Measurements - Additional Information (Detail)
6 Months Ended
Jun. 30, 2020
Position
Schedule of Available-for-sale Securities [Line Items]  
Number of available-for-sale investments 17
Available-for-sale, investments in unrealized loss positions, number of positions, less than twelve months 4
Maximum [Member]  
Schedule of Available-for-sale Securities [Line Items]  
Available-for-sale investments effective maturity period 1 year