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Earnings Per Share - Additional Information (Detail) - shares
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Common Stock        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options to purchase (in shares) 0 0 0 0