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Fair Value Measurements - Additional Information (Detail) - USD ($)
Jun. 30, 2020
Dec. 31, 2019
Jun. 30, 2019
Fair Value Disclosures [Abstract]      
Fair value, assets transfers from Level 1 to Level 2 measurement $ 0   $ 0
Fair value, assets transfers from Level 2 to Level 1 measurement 0   $ 0
Restricted investments $ 1,400,000 $ 1,400,000