Earnings Per Common Share - Summary of Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Numerator for both basic and diluted earnings per common share:
Net income available to common shareholders	$ 34,311	$ 50,502	$ 116,470	$ 132,309
Denominator:
Total average basic common shares outstanding	59,358,653	59,549,244	59,280,644	60,336,637
Effect of dilutive stock options and other stock compensation	84,713	148,432	105,785	152,611
Total diluted average common shares outstanding	59,443,366	59,697,676	59,386,429	60,489,248
Earnings per common share - basic	$ 0.58	$ 0.85	$ 1.96	$ 2.19
Earnings per common share - diluted	$ 0.58	$ 0.85	$ 1.96	$ 2.19