Premises and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Premises and equipment
Premises and equipment, gross	$ 194,780,000	$ 188,179,000
Less: accumulated depreciation and amortization	128,609,000	133,190,000
Total	66,171,000	54,989,000
Depreciation and amortization expense	21,000,000	19,500,000	19,200,000
Reduction in premises and equipment costs	23,800,000
Reduction in accumulated depreciation and amortization	22,800,000
Furniture, fixtures and equipment
Premises and equipment
Premises and equipment, gross	145,226,000	142,235,000
Leasehold improvements
Premises and equipment
Premises and equipment, gross	$ 49,554,000	$ 45,944,000