Premises and Equipment Premises and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Premises and Equipment [Line Items]
Premises and Equipment, Gross	$ 594,698,000	$ 565,343,000
Premises and Equipment, Accumulated depreciation	316,849,000	299,423,000
Premises and Equipment, net	277,849,000	265,920,000
Depreciation Expense	30,000,000	33,000,000	32,000,000
Land [Member]
Premises and Equipment [Line Items]
Premises and Equipment, Gross	75,859,000	73,616,000
Building and improvements [Member]
Premises and Equipment [Line Items]
Premises and Equipment, Gross	221,326,000	214,116,000
Software [Member]
Premises and Equipment [Line Items]
Premises and Equipment, Gross	103,473,000	89,183,000
Furniture and equipment [Member]
Premises and Equipment [Line Items]
Premises and Equipment, Gross	163,013,000	158,020,000
Construction in progress [Member]
Premises and Equipment [Line Items]
Premises and Equipment, Gross	$ 31,027,000	$ 30,408,000