Note 3 - Loans and Allowance for Loan Losses - Impaired Loans (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Originated Loan [Member]
With no related allowance recorded, unpaid principal balance	$ 2,147,000		$ 2,147,000		$ 1,509,000
With no related allowance recorded, principal balance	2,146,000		2,146,000		1,501,000
With no related allowance recorded, average recorded principal balance	2,017,000	$ 1,930,000	1,845,000	$ 1,674,000
With an allowance recorded, unpaid principal balance	249,000		249,000		352,000
With an allowance recorded, principal balance	199,000		199,000		305,000
Related allowance	47,000		47,000		165,000
With an allowance recorded, average recorded principal balance	217,000	2,812,000	246,000	3,617,000
With no related allowance recorded, average recorded principal balance	2,017,000	1,930,000	1,845,000	1,674,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Acquired Loan [Member]
With no related allowance recorded, unpaid principal balance	1,694,000		1,694,000		1,528,000
With no related allowance recorded, principal balance	1,681,000		1,681,000		1,494,000
With no related allowance recorded, average recorded principal balance	1,556,000	1,244,000	1,535,000	1,356,000
With an allowance recorded, unpaid principal balance	356,000		356,000		383,000
With an allowance recorded, principal balance	356,000		356,000		376,000
Related allowance	101,000		101,000		102,000
With an allowance recorded, average recorded principal balance	367,000	97,000	370,000	65,000
With no related allowance recorded, average recorded principal balance	1,556,000	1,244,000	1,535,000	1,356,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Originated Loan [Member]
With no related allowance recorded, unpaid principal balance	0		0		0
With no related allowance recorded, principal balance	0		0		0
With no related allowance recorded, average recorded principal balance	0	98,000	0	135,000
With an allowance recorded, unpaid principal balance	2,002,000		2,002,000		2,017,000
With an allowance recorded, principal balance	1,625,000		1,625,000		1,655,000
Related allowance	72,000		72,000		245,000
With an allowance recorded, average recorded principal balance	1,633,000	2,092,000	1,640,000	2,061,000
With no related allowance recorded, average recorded principal balance	0	98,000	0	135,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Acquired Loan [Member]
With no related allowance recorded, unpaid principal balance	0		0		0
With no related allowance recorded, principal balance	0		0		0
With no related allowance recorded, average recorded principal balance	0	0	0	0
With an allowance recorded, unpaid principal balance	0		0		0
With an allowance recorded, principal balance	0		0		0
Related allowance	0		0		0
With an allowance recorded, average recorded principal balance	0	0	0	0
With no related allowance recorded, average recorded principal balance	0	0	0	0
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Originated Loan [Member]
With no related allowance recorded, unpaid principal balance	348,000		348,000		712,000
With no related allowance recorded, principal balance	251,000		251,000		505,000
With no related allowance recorded, average recorded principal balance	160,000	1,062,000	275,000	1,342,000
With an allowance recorded, unpaid principal balance	5,930,000		5,930,000		5,867,000
With an allowance recorded, principal balance	1,378,000		1,378,000		1,314,000
Related allowance	235,000		235,000		242,000
With an allowance recorded, average recorded principal balance	1,339,000	8,806,000	1,331,000	11,095,000
With no related allowance recorded, average recorded principal balance	160,000	1,062,000	275,000	1,342,000
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Acquired Loan [Member]
With no related allowance recorded, unpaid principal balance	1,314,000		1,314,000		2,233,000
With no related allowance recorded, principal balance	1,300,000		1,300,000		1,952,000
With no related allowance recorded, average recorded principal balance	1,485,000	317,000	1,640,000	249,000
With an allowance recorded, unpaid principal balance	49,000		49,000		51,000
With an allowance recorded, principal balance	49,000		49,000		51,000
Related allowance	4,000		4,000		4,000
With an allowance recorded, average recorded principal balance	50,000	1,256,000	50,000	1,338,000
With no related allowance recorded, average recorded principal balance	1,485,000	317,000	1,640,000	249,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Originated Loan [Member]
With no related allowance recorded, unpaid principal balance	5,623,000		5,623,000		5,696,000
With no related allowance recorded, principal balance	5,623,000		5,623,000		5,696,000
With no related allowance recorded, average recorded principal balance	5,641,000	2,937,000	5,660,000	2,362,000
With an allowance recorded, unpaid principal balance	4,704,000		4,704,000		4,841,000
With an allowance recorded, principal balance	4,704,000		4,704,000		4,841,000
Related allowance	180,000		180,000		201,000
With an allowance recorded, average recorded principal balance	4,729,000	10,319,000	4,766,000	12,195,000
With no related allowance recorded, average recorded principal balance	5,641,000	2,937,000	5,660,000	2,362,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Acquired Loan [Member]
With no related allowance recorded, unpaid principal balance	811,000		811,000		880,000
With no related allowance recorded, principal balance	811,000		811,000		880,000
With no related allowance recorded, average recorded principal balance	792,000	427,000	821,000	393,000
With an allowance recorded, unpaid principal balance	0		0		0
With an allowance recorded, principal balance	0		0		0
Related allowance	0		0		0
With an allowance recorded, average recorded principal balance	0	0	0	0
With no related allowance recorded, average recorded principal balance	792,000	427,000	821,000	393,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member] | Originated Loan [Member]
With no related allowance recorded, unpaid principal balance	0		0		0
With no related allowance recorded, principal balance	0		0		0
With no related allowance recorded, average recorded principal balance	0	306,000	0	309,000
With an allowance recorded, unpaid principal balance	979,000		979,000		1,028,000
With an allowance recorded, principal balance	979,000		979,000		1,028,000
Related allowance	293,000		293,000		365,000
With an allowance recorded, average recorded principal balance	993,000	1,321,000	1,004,000	1,338,000
With no related allowance recorded, average recorded principal balance	0	306,000	0	309,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residentia lRental Loan [Member] | Acquired Loan [Member]
With no related allowance recorded, unpaid principal balance	295,000		295,000		452,000
With no related allowance recorded, principal balance	295,000		295,000		404,000
With no related allowance recorded, average recorded principal balance	289,000	2,037,000	327,000	1,520,000
With an allowance recorded, unpaid principal balance	20,000		20,000		23,000
With an allowance recorded, principal balance	20,000		20,000		23,000
Related allowance	1,000		1,000		0
With an allowance recorded, average recorded principal balance	20,000	28,000	21,000	19,000
With no related allowance recorded, average recorded principal balance	289,000	2,037,000	327,000	1,520,000
Commercial Portfolio Segment [Member] | Originated Loan [Member]
With no related allowance recorded, unpaid principal balance	8,118,000		8,118,000		7,917,000
With no related allowance recorded, principal balance	8,020,000		8,020,000		7,702,000
With no related allowance recorded, average recorded principal balance	7,818,000	6,333,000	7,780,000	5,822,000
With an allowance recorded, unpaid principal balance	13,864,000		13,864,000		14,105,000
With an allowance recorded, principal balance	8,885,000		8,885,000		9,143,000
Related allowance	827,000		827,000		1,218,000
With an allowance recorded, average recorded principal balance	8,911,000	25,350,000	8,987,000	30,306,000
Total, unpaid principal balance	21,982,000		21,982,000		22,022,000
Total, principal balance	16,905,000		16,905,000		16,845,000
Total, average recorded principal balance	16,729,000	31,683,000	16,767,000	36,128,000
With no related allowance recorded, average recorded principal balance	7,818,000	6,333,000	7,780,000	5,822,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member]
With no related allowance recorded, unpaid principal balance	4,114,000		4,114,000		5,093,000
With no related allowance recorded, principal balance	4,087,000		4,087,000		4,730,000
With no related allowance recorded, average recorded principal balance	4,122,000	4,025,000	4,323,000	3,518,000
With an allowance recorded, unpaid principal balance	425,000		425,000		457,000
With an allowance recorded, principal balance	425,000		425,000		450,000
Related allowance	106,000		106,000		106,000
With an allowance recorded, average recorded principal balance	437,000	1,381,000	441,000	1,422,000
Total, unpaid principal balance	4,539,000		4,539,000		5,550,000
Total, principal balance	4,512,000		4,512,000		5,180,000
Total, average recorded principal balance	4,559,000	5,406,000	4,764,000	4,940,000
With no related allowance recorded, average recorded principal balance	4,122,000	4,025,000	4,323,000	3,518,000
Retail Portfolio Segment [Member] | Home Equity and Other [Member] | Originated Loan [Member]
With no related allowance recorded, unpaid principal balance	129,000		129,000		14,000
With no related allowance recorded, principal balance	120,000		120,000		5,000
With no related allowance recorded, average recorded principal balance	65,000	189,000	45,000	190,000
With an allowance recorded, unpaid principal balance	550,000		550,000		600,000
With an allowance recorded, principal balance	512,000		512,000		562,000
Related allowance	137,000		137,000		209,000
With an allowance recorded, average recorded principal balance	491,000	165,000	515,000	138,000
With no related allowance recorded, average recorded principal balance	65,000	189,000	45,000	190,000
Retail Portfolio Segment [Member] | Home Equity and Other [Member] | Acquired Loan [Member]
With no related allowance recorded, unpaid principal balance	367,000		367,000		471,000
With no related allowance recorded, principal balance	365,000		365,000		310,000
With no related allowance recorded, average recorded principal balance	321,000	365,000	317,000	456,000
With an allowance recorded, unpaid principal balance	0		0		0
With an allowance recorded, principal balance	0		0		0
Related allowance	0		0		0
With an allowance recorded, average recorded principal balance	0	0	0	0
With no related allowance recorded, average recorded principal balance	321,000	365,000	317,000	456,000
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member] | Originated Loan [Member]
With no related allowance recorded, unpaid principal balance	1,324,000		1,324,000		1,328,000
With no related allowance recorded, principal balance	668,000		668,000		657,000
With no related allowance recorded, average recorded principal balance	621,000	615,000	633,000	597,000
With an allowance recorded, unpaid principal balance	205,000		205,000		165,000
With an allowance recorded, principal balance	163,000		163,000		128,000
Related allowance	72,000		72,000		47,000
With an allowance recorded, average recorded principal balance	145,000	217,000	139,000	811,000
With no related allowance recorded, average recorded principal balance	621,000	615,000	633,000	597,000
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member] | Acquired Loan [Member]
With no related allowance recorded, unpaid principal balance	1,305,000		1,305,000		1,804,000
With no related allowance recorded, principal balance	1,305,000		1,305,000		1,548,000
With no related allowance recorded, average recorded principal balance	1,290,000	801,000	1,376,000	823,000
With an allowance recorded, unpaid principal balance	174,000		174,000		175,000
With an allowance recorded, principal balance	174,000		174,000		175,000
Related allowance	5,000		5,000		6,000
With an allowance recorded, average recorded principal balance	87,000	283,000	116,000	189,000
With no related allowance recorded, average recorded principal balance	1,290,000	801,000	1,376,000	823,000
Retail Portfolio Segment [Member] | Originated Loan [Member]
With no related allowance recorded, unpaid principal balance	1,453,000		1,453,000		1,342,000
With no related allowance recorded, principal balance	788,000		788,000		662,000
With no related allowance recorded, average recorded principal balance	686,000	804,000	678,000	787,000
With an allowance recorded, unpaid principal balance	755,000		755,000		765,000
With an allowance recorded, principal balance	675,000		675,000		690,000
Related allowance	209,000		209,000		256,000
With an allowance recorded, average recorded principal balance	636,000	382,000	654,000	949,000
Total, unpaid principal balance	2,208,000		2,208,000		2,107,000
Total, principal balance	1,463,000		1,463,000		1,352,000
Total, average recorded principal balance	1,322,000	1,186,000	1,332,000	1,736,000
With no related allowance recorded, average recorded principal balance	686,000	804,000	678,000	787,000
Retail Portfolio Segment [Member] | Acquired Loan [Member]
With no related allowance recorded, unpaid principal balance	1,672,000		1,672,000		2,275,000
With no related allowance recorded, principal balance	1,670,000		1,670,000		1,858,000
With no related allowance recorded, average recorded principal balance	1,611,000	1,166,000	1,693,000	1,279,000
With an allowance recorded, unpaid principal balance	174,000		174,000		175,000
With an allowance recorded, principal balance	174,000		174,000		175,000
Related allowance	5,000		5,000		6,000
With an allowance recorded, average recorded principal balance	87,000	283,000	116,000	189,000
Total, unpaid principal balance	1,846,000		1,846,000		2,450,000
Total, principal balance	1,844,000		1,844,000		2,033,000
Total, average recorded principal balance	1,698,000	1,449,000	1,809,000	1,468,000
With no related allowance recorded, average recorded principal balance	1,611,000	1,166,000	1,693,000	1,279,000
Originated Loan [Member]
With no related allowance recorded, unpaid principal balance	9,571,000		9,571,000		9,259,000
With no related allowance recorded, principal balance	8,808,000		8,808,000		8,364,000
With no related allowance recorded, average recorded principal balance	8,504,000	7,137,000	8,458,000	6,609,000
With an allowance recorded, unpaid principal balance	14,619,000		14,619,000		14,870,000
With an allowance recorded, principal balance	9,560,000		9,560,000		9,833,000
Related allowance	1,036,000		1,036,000		1,474,000
With an allowance recorded, average recorded principal balance	9,547,000	25,732,000	9,641,000	31,255,000
Total, unpaid principal balance	24,190,000		24,190,000		24,129,000
Total, principal balance	18,368,000		18,368,000		18,197,000
Total, average recorded principal balance	18,051,000	32,869,000	18,099,000	37,864,000
With no related allowance recorded, average recorded principal balance	8,504,000	7,137,000	8,458,000	6,609,000
Acquired Loan [Member]
With no related allowance recorded, unpaid principal balance	5,786,000		5,786,000		7,368,000
With no related allowance recorded, principal balance	5,757,000		5,757,000		6,588,000
With no related allowance recorded, average recorded principal balance	5,733,000	5,191,000	6,016,000	4,797,000
With an allowance recorded, unpaid principal balance	599,000		599,000		632,000
With an allowance recorded, principal balance	599,000		599,000		625,000
Related allowance	111,000		111,000		112,000
With an allowance recorded, average recorded principal balance	524,000	1,664,000	557,000	1,611,000
Total, unpaid principal balance	6,385,000		6,385,000		8,000,000
Total, principal balance	6,356,000		6,356,000		$ 7,213,000
Total, average recorded principal balance	6,257,000	6,855,000	6,573,000	6,408,000
With no related allowance recorded, average recorded principal balance	$ 5,733,000	$ 5,191,000	$ 6,016,000	$ 4,797,000