Premises and Equipment, Net Premises and Equipment, Net (Summary of Premises and Equipment) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Abstract]
Land	$ 15,281,000	$ 15,331,000
Buildings and improvements	95,775,000	98,906,000
Leasehold improvements	73,253,000	71,159,000
Fixtures and equipment	69,530,000	66,222,000
Data processing and software	162,833,000	153,282,000
Total premises and equipment	416,672,000	404,900,000
Less accumulated depreciation and amortization	(282,110,000)	(257,521,000)
Premises and equipment, net	134,562,000	147,379,000
Depreciation of premises and equipment	$ 34,100,000	$ 34,900,000	$ 37,200,000