CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS’ EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Preferred Series A	Preferred Series B	Common stock	Preferred Stock	Common stock	Surplus	Retained Earnings	Retained Earnings Preferred Series A	Retained Earnings Preferred Series B	Retained Earnings Common stock	Accumulated Other Comprehensive Loss	Treasury Stock
Beginning balance at Dec. 31, 2017	$ 2,533,165				$ 209,691	$ 92,727	$ 2,060,356	$ 216,733				$ (46,005)	$ (337)
Beginning balance (in shares) at Dec. 31, 2017						264,469
Net income	41,965							41,965
Other comprehensive income (loss), net of tax	(17,557)											(17,557)
Cash dividends declared on preferred stock		$ (1,797)	$ (1,375)						$ (1,797)	$ (1,375)
Cash dividends declared on common stock				$ (36,635)							$ (36,635)
Effect of stock incentive plan, net (in shares)						1,714
Effect of stock incentive plan, net	6,637					$ 355	8,717	(2,266)					(169)
Common stock issued (in shares)						65,007
Common stock issued	738,211					$ 22,742	715,121						348
Ending balance at Mar. 31, 2018	3,245,003				209,691	$ 115,824	2,784,194	199,555				(64,103)	(158)
Ending balance (in shares) at Mar. 31, 2018						331,190
Beginning balance at Dec. 31, 2018	3,350,454				209,691	$ 116,240	2,796,499	299,642				(69,431)	(2,187)
Beginning balance (in shares) at Dec. 31, 2018						331,431
Net income	113,330							113,330
Other comprehensive income (loss), net of tax	16,174											16,174
Cash dividends declared on preferred stock		$ (1,797)	$ (1,375)						$ (1,797)	$ (1,375)
Cash dividends declared on common stock				$ (36,686)							$ (36,686)
Effect of stock incentive plan, net (in shares)						302
Effect of stock incentive plan, net	1,811					$ 226	2,935	(99)					(1,251)
Ending balance at Mar. 31, 2019	$ 3,444,879				$ 209,691	$ 116,466	$ 2,799,434	$ 375,983				$ (53,257)	$ (3,438)
Ending balance (in shares) at Mar. 31, 2019						331,733