Premises and Equipment (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 468,810	$ 448,542
Less: Accumulated depreciation and amortization	(256,536)	(240,526)
Premises and equipment, net	212,274	208,016
Land [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	37,669	35,518
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	258,653	249,026
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	160,424	152,071
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 12,064	$ 11,927

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, at the balance sheet date, of long-lived physical assets used in the normal conduct of business and not intended for resale. This can include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.

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- Definition

Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.

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