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	84,999				84,999
Issuance of stock	2,109	1		2,108
Tax windfall benefit (shortfall expense) on vesting of restricted stock	(31)			(31)
Dividends declared:
Dividends, Common Stock, Cash	(15,549)				(15,549)
Dividends, Preferred Stock, Cash	(931)				(931)
Common stock purchases	(764)					(764)
Common stock reissuance	7					7
Other comprehensive loss, net of tax	75,136						75,136
Ending Balance at Mar. 31, 2016	5,250,300	1,039	50,160	4,231,233	1,156,476	(6,858)	(181,750)
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	92,945				92,945
Issuance of stock	1,807	1		1,806
Dividends declared:
Dividends, Common Stock, Cash	(25,615)				(25,615)
Dividends, Preferred Stock, Cash	(931)				(931)
Common stock purchases	(76,324)			4,518		(80,842)
Other comprehensive loss, net of tax	374						374
Ending Balance at Mar. 31, 2017	$ 5,190,213	$ 1,041	$ 50,160	$ 4,261,346	$ 1,286,706	$ (89,128)	$ (319,912)