Premises and Equipment, Summary Composition (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	$ 553,830
Accumulated Depreciation	286,224
Net Book Value	267,606	$ 274,688
Land [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	52,104
Accumulated Depreciation	0
Net Book Value	52,104	52,790
Land Improvements [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	11,570
Accumulated Depreciation	4,909
Net Book Value	$ 6,661	6,608
Land Improvements [Member] | Maximum [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Lives	15 years
Land Improvements [Member] | Minimum [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Lives	3 years
Buildings [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	$ 261,418
Accumulated Depreciation	119,986
Net Book Value	$ 141,432	139,702
Buildings [Member] | Maximum [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Lives	39 years
Buildings [Member] | Minimum [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Lives	5 years
Computers [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	$ 37,875
Accumulated Depreciation	31,503
Net Book Value	$ 6,372	7,518
Computers [Member] | Maximum [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Lives	5 years
Computers [Member] | Minimum [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Lives	3 years
Furniture, fixtures and other equipment [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	$ 159,094
Accumulated Depreciation	109,300
Net Book Value	$ 49,794	55,747
Furniture, fixtures and other equipment [Member] | Maximum [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Lives	15 years
Furniture, fixtures and other equipment [Member] | Minimum [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Lives	3 years
Leasehold Improvements [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Cost	$ 31,769
Accumulated Depreciation	20,526
Net Book Value	$ 11,243	$ 12,323
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Lives	15 years
Leasehold Improvements [Member] | Minimum [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Lives	3 years