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Segment Information - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Disclosure Of Operating Segments [Line Items]      
Revenues from performance obligations satisfied $ 0 $ 0  
Revenue 338,160,000 425,940,000 $ 425,215,000
ROW (Segment) [Member]      
Disclosure Of Operating Segments [Line Items]      
Revenue 89,206,000 108,869,000  
ROW (Segment) [Member] | One major customer [Member]      
Disclosure Of Operating Segments [Line Items]      
Revenue $ 23,118,000 $ 37,197,000 $ 36,518,000
Percentage of entity's revenue from major customer 6.84% 8.73% 8.59%