Premises and Equipment (Schedule of Premises and Equipment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Total premises and equipment	$ 915,751	$ 1,001,429
Less: Accumulated depreciation and amortization	(498,266)	(556,274)
Premises and equipment, net	417,485	445,155
Land [Member]
Property, Plant and Equipment [Line Items]
Total premises and equipment	97,080	106,656
Building and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total premises and equipment	$ 377,754	403,437
Building and Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful Life (in years)	10 years
Building and Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful Life (in years)	40 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total premises and equipment	$ 41,355	41,095
Leasehold Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful Life (in years)	10 years
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful Life (in years)	40 years
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total premises and equipment	$ 370,458	406,121
Furniture and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful Life (in years)	3 years
Furniture and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful Life (in years)	40 years
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Total premises and equipment	$ 29,104	$ 44,120