Premises and Equipment (Details) (USD $)	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Premises and equipment
Premises and equipment, gross	$ 188,179,000	$ 174,373,000
Less: accumulated depreciation and amortization	133,190,000	131,350,000
Total	54,989,000	43,023,000
Depreciation and amortization expense	19,500,000	19,200,000	21,200,000
Furniture, fixtures and equipment
Premises and equipment
Premises and equipment, gross	142,235,000	141,497,000
Leasehold improvements
Premises and equipment
Premises and equipment, gross	$ 45,944,000	$ 32,876,000

The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement.

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Gross amount of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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- Definition

Amount, net of accumulated depreciation, depletion and amortization, of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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