Earnings Per Common Share - Summary of Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Numerator for both basic and diluted earnings per common share:
Net income available to common shareholders	$ 40,217	$ 68,057	$ 81,807	$ 138,641
Denominator:
Total average basic common shares outstanding	60,036,103	66,894,398	60,736,858	67,078,036
Effect of dilutive stock options and other stock compensation	149,104	172,194	162,412	161,512
Total diluted average common shares outstanding	60,185,207	67,066,592	60,899,270	67,239,548
Earnings per common share - basic	$ 0.67	$ 1.02	$ 1.35	$ 2.07
Earnings per common share - diluted	$ 0.67	$ 1.01	$ 1.34	$ 2.06