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Research and Development - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Schedule Of Research And Development [Line Items]      
Research and development expenses $ 24,070 $ 26,428 $ 26,076
Operating expenses      
Schedule Of Research And Development [Line Items]      
Research and development expenses $ 8,906 $ 9,164 $ 8,455