Note 18 - Fair Value Measurements (Details) - Estimated Fair Values and Related Carrying Amounts of Financial Instruments (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Financial assets:
Financial Assets, Carrying Amount	$ 4,325,841	$ 4,383,100
Financial liabilities:
Financial Liabilities, Carrying Amount	3,911,706	3,979,268
Non-Interest Bearing Transaction Accounts [Member] | Fair Value, Inputs, Level 2 [Member]
Financial liabilities:
Financial Liabilities, Fair Value Measurement	838,543	718,438
Non-Interest Bearing Transaction Accounts [Member]
Financial liabilities:
Financial Liabilities, Carrying Amount	838,543	718,438
Financial Liabilities, Fair Value Measurement	838,543	718,438
Interest Bearing Transaction Accounts and Savings Deposits [Member] | Fair Value, Inputs, Level 2 [Member]
Financial liabilities:
Financial Liabilities, Fair Value Measurement	1,784,040	1,862,618
Interest Bearing Transaction Accounts and Savings Deposits [Member]
Financial liabilities:
Financial Liabilities, Carrying Amount	1,784,040	1,862,618
Financial Liabilities, Fair Value Measurement	1,784,040	1,862,618
Time Deposits [Member] | Fair Value, Inputs, Level 3 [Member]
Financial liabilities:
Financial Liabilities, Fair Value Measurement	1,022,339	1,120,035
Time Deposits [Member]
Financial liabilities:
Financial Liabilities, Carrying Amount	1,019,142	1,116,511
Financial Liabilities, Fair Value Measurement	1,022,339	1,120,035
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Member] | Fair Value, Inputs, Level 2 [Member]
Financial liabilities:
Financial Liabilities, Fair Value Measurement	98,226	107,887
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Member]
Financial liabilities:
Financial Liabilities, Carrying Amount	98,226	107,887
Financial Liabilities, Fair Value Measurement	98,226	107,887
Other Borrowings [Member] | Fair Value, Inputs, Level 2 [Member]
Financial liabilities:
Financial Liabilities, Fair Value Measurement	117,707	117,160
Other Borrowings [Member]
Financial liabilities:
Financial Liabilities, Carrying Amount	115,602	117,090
Financial Liabilities, Fair Value Measurement	117,707	117,160
Subordinated Debentures [Member] | Fair Value, Inputs, Level 2 [Member]
Financial liabilities:
Financial Liabilities, Fair Value Measurement	16,115	12,991
Subordinated Debentures [Member]
Financial liabilities:
Financial Liabilities, Carrying Amount	20,620	20,620
Financial Liabilities, Fair Value Measurement	16,115	12,991
Interest Payable [Member] | Fair Value, Inputs, Level 2 [Member]
Financial liabilities:
Financial Liabilities, Fair Value Measurement	1,442	1,450
Interest Payable [Member]
Financial liabilities:
Financial Liabilities, Carrying Amount	1,442	1,450
Financial Liabilities, Fair Value Measurement	1,442	1,450
Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member]
Financial assets:
Financial Assets, Fair Value Measurement	422,660	539,380
Fair Value, Inputs, Level 2 [Member] | Held-to-Maturity Securities [Member]
Financial assets:
Financial Assets, Fair Value Measurement	800,401	731,445
Fair Value, Inputs, Level 2 [Member] | Interest Receivable [Member]
Financial assets:
Financial Assets, Fair Value Measurement	14,254	15,654
Fair Value, Inputs, Level 3 [Member] | Mortgage Loans Held For Sale [Member]
Financial assets:
Financial Assets, Fair Value Measurement	20,409	9,494
Fair Value, Inputs, Level 3 [Member] | Loans1 [Member]
Financial assets:
Financial Assets, Fair Value Measurement	1,864,660	1,694,748
Fair Value, Inputs, Level 3 [Member] | Loans Acquired, Not Covered By FDIC Loss Share [Member]
Financial assets:
Financial Assets, Fair Value Measurement	392,957	513,676
Fair Value, Inputs, Level 3 [Member] | Loans Acquired, Covered By FDIC Loss Share [Member]
Financial assets:
Financial Assets, Fair Value Measurement	120,413	143,814
Fair Value, Inputs, Level 3 [Member] | FDIC Indemnification Asset [Member]
Financial assets:
Financial Assets, Fair Value Measurement	30,508	48,791
Cash and Cash Equivalents [Member]
Financial assets:
Financial Assets, Carrying Amount	422,660	539,380
Financial Assets, Fair Value Measurement	422,660	539,380
Held-to-Maturity Securities [Member]
Financial assets:
Financial Assets, Carrying Amount	799,963	745,688
Financial Assets, Fair Value Measurement	800,401	731,445
Mortgage Loans Held For Sale [Member]
Financial assets:
Financial Assets, Carrying Amount	20,409	9,494
Financial Assets, Fair Value Measurement	20,409	9,494
Interest Receivable [Member]
Financial assets:
Financial Assets, Carrying Amount	14,254	15,654
Financial Assets, Fair Value Measurement	14,254	15,654
Loans1 [Member]
Financial assets:
Financial Assets, Carrying Amount	1,841,312	1,715,196
Financial Assets, Fair Value Measurement	1,864,660	1,694,748
Loans Acquired, Not Covered By FDIC Loss Share [Member]
Financial assets:
Financial Assets, Carrying Amount	398,967	515,644
Financial Assets, Fair Value Measurement	392,957	513,676
Loans Acquired, Covered By FDIC Loss Share [Member]
Financial assets:
Financial Assets, Carrying Amount	121,524	146,653
Financial Assets, Fair Value Measurement	120,413	143,814
FDIC Indemnification Asset [Member]
Financial assets:
Financial Assets, Carrying Amount	30,508	48,791
Financial Assets, Fair Value Measurement	$ 30,508	$ 48,791