Consolidated Statement of Changes in Shareholders' Equity (USD $)	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), Net of Tax [Member]	Treasury Stock [Member]
Beginning balance at Dec. 31, 2010	$ 2,061,680,000	$ 0	$ 611,000	$ 657,335,000	$ 1,249,484,000	$ 154,250,000	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	217,535,000				217,535,000
Other comprehensive loss, net of tax	93,484,000					93,484,000
Stock option exercises/deferred stock unit conversions	7,438,000		1,000	7,065,000	(50,000)		422,000
Tax benefits from stock-based compensation	316,000			316,000
Stock-based compensation expense recognized in earnings	15,963,000			15,963,000
Non-vested stock awards and stock units	0			(1,235,000)			1,235,000
Purchase of treasury stock	(2,029,000)						(2,029,000)
Common stock issued/sold to the 401(k) stock purchase plan	1,360,000		1,000	1,359,000
Cash dividends – common stock	(112,210,000)				(112,210,000)
Ending balance at Dec. 31, 2011	2,283,537,000	0	613,000	680,803,000	1,354,759,000	247,734,000	(372,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	237,952,000				237,952,000
Other comprehensive loss, net of tax	(9,686,000)					(9,686,000)
Stock option exercises/deferred stock unit conversions	10,516,000		2,000	10,100,000	(6,000)		420,000
Tax benefits from stock-based compensation	(384,000)			(384,000)
Stock-based compensation expense recognized in earnings	12,836,000			12,836,000
Non-vested stock awards and stock units	0			(387,000)	(1,000)		388,000
Purchase of treasury stock	(436,000)						(436,000)
Cash dividends – common stock	(116,853,000)				(116,853,000)
Ending balance at Dec. 31, 2012	2,417,482,000	0	615,000	702,968,000	1,475,851,000	238,048,000	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	237,866,000				237,866,000
Other comprehensive loss, net of tax	(97,614,000)					(97,614,000)
Stock option exercises/deferred stock unit conversions	68,653,000		2,000	7,839,000	(12,097,000)		72,909,000
Tax benefits from stock-based compensation	2,293,000			2,293,000
Stock-based compensation expense recognized in earnings	11,963,000			11,963,000
Non-vested stock awards and stock units	0			(866,000)			866,000
Issuance of preferred stock	144,486,000	144,486,000
Purchase of treasury stock	(144,630,000)						(144,630,000)
Cash dividends – preferred stock	(6,719,000)				(6,719,000)
Cash dividends – common stock	(119,619,000)				(119,619,000)
Ending balance at Dec. 31, 2013	$ 2,514,161,000	$ 144,486,000	$ 617,000	$ 724,197,000	$ 1,575,282,000	$ 140,434,000	$ (70,855,000)