Premises and Equipment (Details) (USD $)	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Premises and Equipment
Premises and equipment, gross	$ 129,457,000	$ 124,082,000
Less accumulated depreciation	58,390,000	54,684,000
Total premises and equipment	71,067,000	69,398,000
Depreciation expense	5,400,000	5,500,000	6,200,000
Land and improvements
Premises and Equipment
Premises and equipment, gross	22,732,000	23,238,000
Buildings and improvements
Premises and Equipment
Premises and equipment, gross	65,099,000	62,520,000
Furniture and equipment
Premises and Equipment
Premises and equipment, gross	$ 41,626,000	$ 38,324,000

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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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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- Definition

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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