Note 4 - Loans and Allowance for Loan Losses (Details) - Activity in Allowance for Loan Losses and the Recorded Investments in Loans (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Allowance for loan losses:
Provision for loan losses	$ (400,000)	$ (1,700,000)	$ (3,000,000)	$ (4,700,000)
Total loans:
Loans	2,068,265,000		2,068,265,000		1,053,243,000
Originated Loan [Member] | Commercial Portfolio Segment [Member]
Allowance for loan losses:
Allowance for loan losses	19,107,000	22,382,000	20,455,000	26,043,000
Allowance for loan losses: individually evaluated for impairment	10,485,000	13,860,000	10,485,000	13,860,000
Allowance for loan losses: collectively evaluated for impairment	8,227,000	8,794,000	8,227,000	8,794,000
Provision for loan losses	(473,000)	(1,730,000)	(2,251,000)	(4,375,000)
Charge-offs	(24,000)	0	(708,000)	(2,774,000)
Recoveries	102,000	2,002,000	1,216,000	3,760,000
Allowance for loan losses	18,712,000	22,654,000	18,712,000	22,654,000
Total loans:
Loans	1,103,802,000	1,007,763,000	1,103,802,000	1,007,763,000	986,696,000
Loans: individually evaluated for impairment	48,870,000	46,426,000	48,870,000	46,426,000
Loans: collectively evaluated for impairment	1,054,932,000	961,337,000	1,054,932,000	961,337,000
Originated Loan [Member] | Retail Loan [Member]
Allowance for loan losses:
Allowance for loan losses	1,774,000	2,559,000	2,358,000	2,645,000
Allowance for loan losses: individually evaluated for impairment	879,000	1,203,000	879,000	1,203,000
Allowance for loan losses: collectively evaluated for impairment	798,000	1,295,000	798,000	1,295,000
Provision for loan losses	63,000	(7,000)	(726,000)	(379,000)
Charge-offs	(321,000)	(85,000)	(328,000)	(107,000)
Recoveries	161,000	31,000	373,000	339,000
Allowance for loan losses	1,677,000	2,498,000	1,677,000	2,498,000
Total loans:
Loans	82,911,000	67,724,000	82,911,000	67,724,000	66,547,000
Loans: individually evaluated for impairment	3,346,000	3,851,000	3,346,000	3,851,000
Loans: collectively evaluated for impairment	79,565,000	63,873,000	79,565,000	63,873,000
Originated Loan [Member] | Unallocated Financing Receivables [Member]
Allowance for loan losses:
Allowance for loan losses	(25,000)	6,000	8,000	(11,000)
Allowance for loan losses: individually evaluated for impairment	0	0	0	0
Allowance for loan losses: collectively evaluated for impairment	(15,000)	43,000	(15,000)	43,000
Provision for loan losses	10,000	37,000	(23,000)	54,000
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses	(15,000)	43,000	(15,000)	43,000
Originated Loan [Member]
Allowance for loan losses:
Allowance for loan losses	20,856,000	24,947,000	22,821,000	28,677,000
Allowance for loan losses: individually evaluated for impairment	11,364,000	15,063,000	11,364,000	15,063,000
Allowance for loan losses: collectively evaluated for impairment	9,010,000	10,132,000	9,010,000	10,132,000
Provision for loan losses	(400,000)	(1,700,000)	(3,000,000)	(4,700,000)
Charge-offs	(345,000)	(85,000)	(1,036,000)	(2,881,000)
Recoveries	263,000	2,033,000	1,589,000	4,099,000
Allowance for loan losses	20,374,000	25,195,000	20,374,000	25,195,000
Total loans:
Loans	1,186,713,000	1,075,487,000	1,186,713,000	1,075,487,000	1,053,243,000
Loans: individually evaluated for impairment	52,216,000	50,277,000	52,216,000	50,277,000
Loans: collectively evaluated for impairment	1,134,497,000	1,025,210,000	1,134,497,000	1,025,210,000
Commercial Portfolio Segment [Member]
Total loans:
Loans	1,686,564,000		1,686,564,000		986,696,000
Retail Loan [Member]
Total loans:
Loans	$ 381,701,000		$ 381,701,000		$ 66,547,000