Premises and Equipment (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	$ 481,767
Accumulated Depreciation	(258,031)
Premises and equipment,net	223,736	190,533
Land
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	44,581
Accumulated Depreciation	0
Premises and equipment,net	44,581	43,744
Land improvements
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life Minimum	3
Estimated Useful Life Maximum	15
Cost	9,423
Accumulated Depreciation	(3,114)
Premises and equipment,net	6,309	2,780
Buildings
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life Minimum	5
Estimated Useful Life Maximum	39
Cost	210,810
Accumulated Depreciation	(110,564)
Premises and equipment,net	100,246	95,776
Computers
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life Minimum	3
Estimated Useful Life Maximum	5
Cost	41,534
Accumulated Depreciation	(29,543)
Premises and equipment,net	11,991	9,897
Furniture, fixtures and other equipment
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life Minimum	3
Estimated Useful Life Maximum	15
Cost	145,985
Accumulated Depreciation	(95,093)
Premises and equipment,net	50,892	31,864
Leasehold improvements
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life Minimum	5
Estimated Useful Life Maximum	30
Cost	29,434
Accumulated Depreciation	(19,717)
Premises and equipment,net	$ 9,717	$ 6,472