Income Per Common Share - Additional Information (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Dilutive effect of outstanding restricted stock awards after application of the Treasury Stock Method	219,000	92,000	188,000	98,000
Common stock shares excluded from calculation of diluted net income per common share			500