Note 5 - Loans and Allowance for Credit Losses (Details) - Allowance for Credit Losses by Portfolio Segment (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	$ 46,075	$ 40,921
Loans charged-off	(1,806)	(1,125)
Recoveries of loans previously charged-off	200	288
Net loan charged-off	(1,606)	(837)
Provision for credit losses	3,310us-gaap_ProvisionForLoanAndLeaseLosses	1,934us-gaap_ProvisionForLoanAndLeaseLosses
Ending balance	47,779	42,018
For the period ended March 31, 2015
Individually evaluated for impairment	7,583	7,888
Collectively evaluated for impairment	40,196	34,130
Ending balance	47,779	42,018	46,075
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	13,222	9,780
Loans charged-off	(998)	(273)
Recoveries of loans previously charged-off	51	211
Net loan charged-off	(947)	(62)
Provision for credit losses	1,502	1,702
Ending balance	13,777	11,420
For the period ended March 31, 2015
Individually evaluated for impairment	5,771	3,810
Collectively evaluated for impairment	8,006	7,610
Ending balance	13,777	11,420
Commercial Real Estate Investment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	11,442	10,359
Loans charged-off	(318)
Net loan charged-off	(318)
Provision for credit losses	528	231
Ending balance	11,652	10,590
For the period ended March 31, 2015
Individually evaluated for impairment	568	732
Collectively evaluated for impairment	11,084	9,858
Ending balance	11,652	10,590
Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	2,954	3,899
Loans charged-off		(35)
Recoveries of loans previously charged-off	1
Net loan charged-off	1	(35)
Provision for credit losses	172	(669)
Ending balance	3,127	3,195
For the period ended March 31, 2015
Individually evaluated for impairment	400	1,105
Collectively evaluated for impairment	2,727	2,090
Ending balance	3,127	3,195
Residential Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	1,259	944
Loans charged-off		(62)
Recoveries of loans previously charged-off	2
Net loan charged-off	2	(62)
Provision for credit losses	(206)	(128)
Ending balance	1,055	754
For the period ended March 31, 2015
Individually evaluated for impairment		30
Collectively evaluated for impairment	1,055	724
Ending balance	1,055	754
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	1,469	1,871
Loans charged-off	(419)	(149)
Recoveries of loans previously charged-off	2	5
Net loan charged-off	(417)	(144)
Provision for credit losses	457	(220)
Ending balance	1,509	1,507
For the period ended March 31, 2015
Individually evaluated for impairment	289	378
Collectively evaluated for impairment	1,220	1,129
Ending balance	1,509	1,507
Consumer, Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	104	134
Loans charged-off	(71)	(25)
Recoveries of loans previously charged-off	49	7
Net loan charged-off	(22)	(18)
Provision for credit losses	194	257
Ending balance	276	373
For the period ended March 31, 2015
Individually evaluated for impairment	5	58
Collectively evaluated for impairment	271	315
Ending balance	276	373
Construction Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	15,625	13,934
Loans charged-off		(581)
Recoveries of loans previously charged-off	95	65
Net loan charged-off	95	(516)
Provision for credit losses	663	761
Ending balance	16,383	14,179
For the period ended March 31, 2015
Individually evaluated for impairment	550	1,775
Collectively evaluated for impairment	15,833	12,404
Ending balance	$ 16,383	$ 14,179

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Amount of other addition (reduction) in allowance reserve for credit loss.

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-Publisher FASB

-Name Accounting Standards Codification

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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A valuation allowance for financing receivables that are expected to be uncollectible.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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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 expense related to estimated loss from loan and lease transactions.

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