Earnings Per Common Share - Basic and Diluted Earnings Per Common Share (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Earnings Per Share [Abstract]
Net income	$ 172,059	$ 157,003	$ 343,046	$ 307,925
Less: Preferred stock dividends	1,669	1,669	3,338	3,338
Net income available to common shareholders	170,390	155,334	339,708	304,587
Less: Earnings allocated to participating securities	1,991	1,492	4,108	2,956
Distributed earnings allocated to common stock	64,013	64,310	127,139	125,377
Undistributed earnings allocated to common stock	104,386	89,532	208,461	176,254
Net earnings allocated to common stock	$ 168,399	$ 153,842	$ 335,600	$ 301,631
Weighted-average shares outstanding for basic earnings per common share	62,454,716	64,299,943	62,776,317	64,277,718
Dilutive effect of stock compensation	0	51,837	0	62,481
Weighted-average shares outstanding for diluted earnings per common share	62,454,716	64,351,780	62,776,317	64,340,199