Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Securities available-for-sale, amortized cost	$ 1,981,977	$ 2,087,069
Less: Unearned income on loans	(53,867)	(59,374)
Loans and Leases Receivable, Allowance	70,234	69,569
Other real estate owned covered by FDIC loss share	$ 23,299	$ 22,190
Common stock, par value	$ 0us-gaap_CommonStockNoParValue	$ 0us-gaap_CommonStockNoParValue
Authorized shares	63,033us-gaap_CommonStockSharesAuthorized	63,033us-gaap_CommonStockSharesAuthorized
Common stock, shares outstanding	57,699us-gaap_CommonStockSharesOutstanding	57,437us-gaap_CommonStockSharesOutstanding

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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Face amount per share of no-par value common stock.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

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Carrying amount as of the balance sheet date of land and buildings obtained through foreclosure proceedings or defeasance in full or partial satisfaction of a debt arrangement.

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