Earnings Per Common Share - Summary of Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Numerator for both basic and diluted earnings per common share:
Net income	$ 23,396	$ 40,337
Denominator:
Total average basic common shares outstanding	67,486,550	54,598,499
Effect of dilutive stock options and other stock compensation	100,896	107,838
Total diluted average common shares outstanding	67,587,446	54,706,337
Earnings per common share - basic	$ 0.35	$ 0.74
Earnings per common share - diluted	$ 0.35	$ 0.74