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, 2014	$ 4,267,382	$ 1,036	$ 50,160	$ 4,196,458	$ 253,717	$ (4,117)	$ (229,872)
Net Income	74,826				74,826
Issuance of stock	1,406	1		1,405
Tax windfall benefit (shortfall expense) on vesting of restricted stock	69			69
Dividends declared:
Dividends, Preferred Stock, Cash	(930)				(930)
Common stock purchases	(1,123)					(1,123)
Common stock reissuance	18					18
Other comprehensive loss, net of tax	35,472						35,472
Ending Balance at Mar. 31, 2015	4,377,120	1,037	50,160	4,197,932	327,613	(5,222)	(194,400)
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)