Consolidated Statements of Changes in Shareholders' Equity (USD $) In Thousands	Total	Preferred Stock	Common Stock	Capital Surplus	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Treasury Stock
Beginning Balance at Dec. 31, 2009	$ 1,065,627		$ 127,937	$ 88,573	$ (25,459)	$ 1,043,625	$ (169,049)
Net income	102,909					102,909
Cash dividends - common stock	(65,634)					(65,634)
Options exercised	826			(330)			1,156
Nonvested (restricted) shares granted	0			(10,973)			10,973
Treasury Stock, Value, Acquired, Cost Method	(2,634)			1,227			(3,861)
Deferred compensation trust	0			(195)			195
Share-based compensation	7,247			7,247
Issuance of common stock	400,018			400,018
Net unrealized gains on investment securities, net of taxes	(1,111)				(1,111)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax	467				467
Ending Balance at Dec. 31, 2010	1,507,715	0	127,937	485,567	(26,103)	1,080,900	(160,586)
Net income	119,558					119,558
Cash dividends - common stock	(69,255)					(69,255)
Nonvested (restricted) shares granted	0			(14,222)			14,222
Treasury Stock, Value, Acquired, Cost Method	(2,295)			602			(2,897)
Deferred compensation trust	0			(79)			79
Share-based compensation	8,014			8,014
Net unrealized gains on investment securities, net of taxes	19,002				19,002
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax	(16,786)				(16,786)
Ending Balance at Dec. 31, 2011	1,565,953	0	127,937	479,882	(23,887)	1,131,203	(149,182)
Net income	134,106					134,106
Cash dividends - common stock	(69,459)					(69,459)
Nonvested (restricted) shares granted	49			(14,582)			14,631
Treasury Stock, Value, Acquired, Cost Method	(2,389)			1,219			(3,608)
Deferred compensation trust	0			200			(200)
Share-based compensation	9,260			9,260			0
Net unrealized gains on investment securities, net of taxes	1,693				1,693
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax	5,989				5,989
Ending Balance at Dec. 31, 2012	$ 1,645,202	$ 0	$ 127,937	$ 475,979	$ (16,205)	$ 1,195,850	$ (138,359)