Earnings Per Common Share - Additional Information (Detail) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Stock Option [Member]
Schedule Of Antidilutive Securities Included In Computation Of Earnings Per Share [Line Items]
Securities excluded from computation of net income per diluted shares	393,961	510,186
Restricted Stock [Member]
Schedule Of Antidilutive Securities Included In Computation Of Earnings Per Share [Line Items]
Shares contingently issuable under shareholder return plan	0	25,618