Note 12 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Financial Assets
Securities held-to-maturity		$ 823,906
Securities available-for-sale	2,018,305	1,291,480
Trading securities	4,816	4,703
Estimate of Fair Value Measurement [Member]
Financial Assets
Cash and due from banks	133,003	144,909
Short-term investments	139,840	411,983
Securities held-to-maturity		823,906
Securities available-for-sale	2,018,305	1,291,480
Trading securities	4,816	4,703
Loans, net	7,418,305	7,169,732
Investment in Federal Home Loan Bank stock	32,918	41,272
Warrants	72	104
Financial Liabilities
Deposits	7,716,124	7,389,015
Securities sold under agreement to repurchase	1,019,835	1,361,585
Advances from Federal Home Loan Bank	126,310	146,789
Other borrowings	14,680	14,573
Long-term debt	97,375	98,392
Fair Value, Inputs, Level 1 [Member]
Financial Assets
Cash and due from banks	133,003	144,909
Short-term investments	139,840	411,983
Securities held-to-maturity		0
Securities available-for-sale	415,874	526,165
Trading securities	0	0
Loans, net	0	0
Investment in Federal Home Loan Bank stock	0	0
Warrants	0	0
Financial Liabilities
Deposits	0	0
Securities sold under agreement to repurchase	0	0
Advances from Federal Home Loan Bank	0	0
Other borrowings	0	0
Long-term debt	0	0
Fair Value, Inputs, Level 2 [Member]
Financial Assets
Cash and due from banks	0	0
Short-term investments	0	0
Securities held-to-maturity		823,906
Securities available-for-sale	1,602,431	765,315
Trading securities	4,703	4,703
Loans, net	0	0
Investment in Federal Home Loan Bank stock	32,918	41,272
Warrants	0	0
Financial Liabilities
Deposits	0	0
Securities sold under agreement to repurchase	1,019,835	1,361,585
Advances from Federal Home Loan Bank	126,310	146,789
Other borrowings	0	0
Long-term debt	97,375	98,392
Fair Value, Inputs, Level 3 [Member]
Financial Assets
Cash and due from banks	0	0
Short-term investments	0	0
Securities held-to-maturity		0
Securities available-for-sale	0	0
Trading securities	113	0
Loans, net	7,418,305	7,169,732
Investment in Federal Home Loan Bank stock	0	0
Warrants	72	104
Financial Liabilities
Deposits	7,716,124	7,389,015
Securities sold under agreement to repurchase	0	0
Advances from Federal Home Loan Bank	0	0
Other borrowings	14,680	14,573
Long-term debt	$ 0	$ 0

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- Definition

Other borrowings fair value disclosure.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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- Definition

Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

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No definition available.

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- Definition

Fair value portion of borrowing from Federal Home Loan Bank (FHLBank).

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Fair value of investments in debt securities classified as held-to-maturity.

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Fair value portion of investments in Federal Home Loan Bank (FHLBank) stock.

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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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Fair value portion of securities that an entity sells and agrees to repurchase at a specified date for a specified price.

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Investments which are intended to be sold in the short term (usually less than one year or the normal operating cycle, whichever is longer) including trading securities, available-for-sale securities, held-to-maturity securities, and other short-term investments not otherwise listed in the existing taxonomy.

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-Subparagraph g

-Article 7

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Amount of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

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