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Related Party Transactions - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Related Party Transaction [Line Items]    
Purchase of non-controlling interests $ 499,000 $ 65,000
Partnership And Trust [Member]    
Related Party Transaction [Line Items]    
Purchase of non-controlling interests $ 499,000 $ 65,000
Related Party [Member]    
Related Party Transaction [Line Items]    
Purchase of treasury stock shares 0 10,000