Consolidated Statements Of Changes In Equity (USD $) In Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Non-Controlling Interest [Member]
Balance at Dec. 31, 2012	$ 2,171,574	$ 0	$ 458,646	$ 1,102,507	$ 477,210	$ (7,580)	$ 136,344	$ 4,447
Net income	126,847				126,822			25
Other comprehensive income	(114,480)						(114,480)
Distributions to non-controlling interest	(512)							(512)
Issuance of preferred stock	0
Purchase of treasury stock	(45,292)					(45,292)
Issuance of stock under purchase and equity compensation plans	6,559			(2,488)		9,047
Net tax benefit related to equity compensation plans	209			209
Stock-based compensation	2,748			2,748
Issuance of nonvested stock awards	0			(8,054)		8,054
Cash dividends	(40,866)				(40,866)
Balance at Jun. 30, 2013	2,106,787	0	458,646	1,094,922	563,166	(35,771)	21,864	3,960
Balance at Dec. 31, 2013	2,214,397	0	481,224	1,279,948	449,836	(10,097)	9,731	3,755
Net income	130,021				130,844			(823)
Other comprehensive income	74,583						74,583
Distributions to non-controlling interest	(554)							(554)
Issuance of preferred stock	144,816	144,816
Purchase of treasury stock	(208,989)					(208,989)
Accelerated share repurchase forward contract	(60,000)			(60,000)
Issuance of stock under purchase and equity compensation plans	5,241			(3,670)		8,911
Net tax benefit related to equity compensation plans	1,091			1,091
Stock-based compensation	4,468			4,468
Issuance of nonvested stock awards	0			(7,001)		7,001
Cash dividends	(42,921)				(42,921)
Balance at Jun. 30, 2014	$ 2,262,153	$ 144,816	$ 481,224	$ 1,214,836	$ 537,759	$ (203,174)	$ 84,314	$ 2,378