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Fair Value Disclosures - Additional Information (Detail) - USD ($)
$ in Thousands
Mar. 31, 2021
Dec. 31, 2020
Fair Value, Option, Quantitative Disclosures [Line Items]    
Equity method investments at fair value $ 4,665 $ 6,307
Level 3    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Equity method investments at fair value $ 4,665 $ 6,307