CONSOLIDATED STATEMENT OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) (USD $) In Thousands, unless otherwise specified	Total	Preferred stock [Member]	Common stock [Member]	Common stock issuable [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Accumulated other comprehensive income (loss), net [Member]
Beginning Balance at Dec. 31, 2012	$ 10,202,593	$ 872,500	$ 64,088	$ 3,473	$ 3,025,520	$ 6,477,276	$ (240,264)
Total comprehensive income	288,424					274,113	14,311
Preferred stock cash dividends	(13,363)					(13,363)
Amortization of preferred stock discount		2,127				(2,127)
Exercise of stock warrants into common stock			93		(93)
Stock-based compensation plans:
Compensation expense, net	13,071		160		12,911
Exercises of stock options, net	21,570		126		21,444
Directors' stock plan	776		4		772
Deferred compensation plans, net, including dividend equivalents	(108)		5	(644)	563	(32)
Other	666				666
Common stock cash dividends - $.70 per share	(90,672)					(90,672)
Ending Balance at Mar. 31, 2013	10,422,957	874,627	64,476	2,829	3,061,783	6,645,195	(225,953)
Beginning Balance at Dec. 31, 2013	11,305,532	881,500	65,258	2,915	3,232,014	7,188,004	(64,159)
Total comprehensive income	267,915					229,017	38,898
Preferred stock cash dividends	(14,674)					(14,674)
Issuance of Series E preferred stock	346,500	350,000			(3,500)
Stock-based compensation plans:
Compensation expense, net	14,122		123		13,999
Exercises of stock options, net	49,494		266		49,228
Stock purchase plan	9,588		43		9,545
Directors' stock plan	441		2		439
Deferred compensation plans, net, including dividend equivalents	(61)		2	(299)	265	(29)
Other	412				412
Common stock cash dividends - $.70 per share	(92,406)					(92,406)
Ending Balance at Mar. 31, 2014	$ 11,886,863	$ 1,231,500	$ 65,694	$ 2,616	$ 3,302,402	$ 7,309,912	$ (25,261)