Consolidated Statements of Changes in Shareholders' Equity (unaudited) - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Capital Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2022	$ 5,128,595	$ 230,500	$ 292,903	$ 4,174,265	$ 1,217,349	$ (786,422)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	146,600				146,600
Other comprehensive income (loss)	78,064					78,064
Cash dividends:
Dividends - common stock	(41,088)				(41,088)
Preferred ($17.50 per share)	(4,034)				(4,034)
Common stock issued	262		15	247
Common stock repurchased	(43,710)		(2,598)	(41,112)
Share-based compensation expense	12,742			12,742
Stock activity under incentive compensation plans	(5)		1,602	(1,412)	(195)
Ending balance at Mar. 31, 2023	5,277,426	230,500	291,922	4,144,730	1,318,632	(708,358)
Beginning balance at Dec. 31, 2023	5,562,900	230,500	292,655	4,159,924	1,618,630	(738,809)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	120,284				120,284
Other comprehensive income (loss)	(40,819)					(40,819)
Cash dividends:
Dividends - common stock	(41,060)				(41,060)
Preferred ($17.50 per share)	(4,034)				(4,034)
Common stock issued	265		17	248
Common stock repurchased	(7,182)		(434)	(6,748)
Share-based compensation expense	5,491			5,491
Stock activity under incentive compensation plans	(437)		1,092	(1,373)	(156)
Ending balance at Mar. 31, 2024	$ 5,595,408	$ 230,500	$ 293,330	$ 4,157,542	$ 1,693,664	$ (779,628)