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Computation of 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
Stock Options [Member]        
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Antidilutive shares excluded from calculation of earnings per share 15,000 0 15,000 0