CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Preferred Stock	Surplus	Retained earnings	Treasury Stock	Accumulated other comprehensive income (loss)
Beginning Balance at Dec. 31, 2015	$ 5,105,324	$ 1,038	$ 50,160	$ 4,229,156	$ 1,087,957	$ (6,101)	$ (256,886)
Net Income	220,796				220,796
Issuance of stock	5,718	2		5,716
Tax windfall benefit (shortfall expense) on vesting of restricted stock	(30)			(30)
Dividends declared:
Dividends, Common Stock, Cash	(46,666)				(46,666)
Dividends, Preferred Stock, Cash	(2,792)				(2,792)
Common stock purchases	(1,563)					(1,563)
Common stock reissuance	17					17
Other comprehensive loss, net of tax	99,591						99,591
Ending Balance at Sep. 30, 2016	5,380,395	1,040	50,160	4,234,842	1,259,295	(7,647)	(157,295)
Beginning Balance at Dec. 31, 2016	5,197,957	1,040	50,160	4,255,022	1,220,307	(8,286)	(320,286)
Net Income	209,835				209,835
Issuance of stock	5,515	2		5,513
Dividends declared:
Dividends, Common Stock, Cash	(76,620)				(76,620)
Dividends, Preferred Stock, Cash	(2,792)				(2,792)
Common stock purchases	(77,418)			4,518		(81,936)
Other comprehensive loss, net of tax	28,954						28,954
Ending Balance at Sep. 30, 2017	$ 5,285,431	$ 1,042	$ 50,160	$ 4,265,053	$ 1,350,730	$ (90,222)	$ (291,332)