Note 4 - Loans and Allowance for Loan Losses (Details) - Activity in Allowance for Loan Losses and the Recorded Investments in Loans (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	$ 22,821,000	$ 28,677,000	$ 36,532,000
Allowance for loan losses: individually evaluated for impairment		12,386,000	17,189,000
Allowance for loan losses: collectively evaluated for impairment		10,435,000	11,488,000
Total loans:
Loans	2,089,277,000	1,053,243,000	1,041,189,000
Loans: individually evaluated for impairment		36,868,000	57,279,000
Loans: collectively evaluated for impairment		1,016,375,000	983,910,000
Provision for loan losses	(3,000,000)	(7,200,000)	(3,100,000)
Charge-offs		(5,290,000)	(12,644,000)
Recoveries		6,634,000	7,889,000
Allowance for loan losses		22,821,000	28,677,000
Originated Loan [Member] \| Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	20,455,000
Allowance for loan losses: individually evaluated for impairment	9,374,000
Allowance for loan losses: collectively evaluated for impairment	8,362,000
Total loans:
Loans	1,153,189,000	986,696,000
Loans: individually evaluated for impairment	45,021,000
Loans: collectively evaluated for impairment	1,108,168,000
Provision for loan losses	(3,140,000)
Charge-offs	(876,000)
Recoveries	1,297,000
Allowance for loan losses	17,736,000
Originated Loan [Member] \| Retail Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	2,358,000
Allowance for loan losses: individually evaluated for impairment	777,000
Allowance for loan losses: collectively evaluated for impairment	710,000
Total loans:
Loans	92,927,000	66,547,000
Loans: individually evaluated for impairment	2,835,000
Loans: collectively evaluated for impairment	90,092,000
Provision for loan losses	(721,000)
Charge-offs	(554,000)
Recoveries	404,000
Allowance for loan losses	1,487,000
Originated Loan [Member] \| Unallocated Financing Receivables [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	8,000
Allowance for loan losses: individually evaluated for impairment	0
Allowance for loan losses: collectively evaluated for impairment	76,000
Total loans:
Provision for loan losses	68,000
Charge-offs	0
Recoveries	0
Allowance for loan losses	76,000
Originated Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	22,821,000
Allowance for loan losses: individually evaluated for impairment	10,151,000
Allowance for loan losses: collectively evaluated for impairment	9,148,000
Total loans:
Loans	1,246,116,000	1,053,243,000
Loans: individually evaluated for impairment	47,856,000
Loans: collectively evaluated for impairment	1,198,260,000
Provision for loan losses	(3,793,000)
Charge-offs	(1,430,000)
Recoveries	1,701,000
Allowance for loan losses	19,299,000
Acquired Loan [Member] \| Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	0
Total loans:
Loans	562,114,000	0
Provision for loan losses	734,000
Charge-offs	(55,000)
Recoveries	2,000
Allowance for loan losses	681,000
Acquired Loan [Member] \| Retail Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	0
Total loans:
Loans	281,047,000	0
Provision for loan losses	59,000
Charge-offs	(16,000)
Recoveries	18,000
Allowance for loan losses	61,000
Acquired Loan [Member] \| Unallocated Financing Receivables [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	0
Total loans:
Provision for loan losses	0
Charge-offs	0
Recoveries	0
Allowance for loan losses	0
Acquired Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	0
Total loans:
Loans	843,161,000	0
Provision for loan losses	793,000
Charge-offs	(71,000)
Recoveries	20,000
Allowance for loan losses	742,000
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses		26,043,000	33,431,000
Allowance for loan losses: individually evaluated for impairment		11,260,000	16,860,000
Allowance for loan losses: collectively evaluated for impairment		9,195,000	9,183,000
Total loans:
Loans	1,715,303,000	986,696,000	968,506,000
Loans: individually evaluated for impairment		33,240,000	55,138,000
Loans: collectively evaluated for impairment		953,456,000	913,368,000
Provision for loan losses		(6,730,000)	(2,800,000)
Charge-offs		(5,120,000)	(12,075,000)
Recoveries		6,262,000	7,487,000
Allowance for loan losses		20,455,000	26,043,000
Retail Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses		2,645,000	3,019,000
Allowance for loan losses: individually evaluated for impairment		1,126,000	329,000
Allowance for loan losses: collectively evaluated for impairment		1,232,000	2,316,000
Total loans:
Loans	373,974,000	66,547,000	72,683,000
Loans: individually evaluated for impairment		3,628,000	2,141,000
Loans: collectively evaluated for impairment		62,919,000	70,542,000
Provision for loan losses		(489,000)	(207,000)
Charge-offs		(170,000)	(569,000)
Recoveries		372,000	402,000
Allowance for loan losses		2,358,000	2,645,000
Unallocated Financing Receivables [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses		(11,000)	82,000
Allowance for loan losses: individually evaluated for impairment		0	0
Allowance for loan losses: collectively evaluated for impairment		8,000	(11,000)
Total loans:
Provision for loan losses		19,000	(93,000)
Charge-offs		0	0
Recoveries		0	0
Allowance for loan losses		$ 8,000	$ (11,000)

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

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

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Amount of recovery of financing receivables doubtful of collection that were previously charged off.

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Amount of direct write-downs of financing receivables charged against the allowance.

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The balance of financing receivables that were collectively evaluated for impairment.

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Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

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