Note 4 - Loans and Allowance for Loan Losses - Activity in the Allowance for Loan Losses, by Portfolio Segment, for the Current Year (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Balance, beginning of year	$ 31,351,000
Provision for loan losses	20,065,000		$ 9,022,000		$ 7,245,000
Balance, end of year	36,286,000		31,351,000
Loans, Excluding Acquired Loans [Member]
Balance, beginning of year	31,351,000	[1]	29,028,000	[1]	27,442,000
Provision for loan losses	19,439,000	[2]	8,286,000	[2]	6,882,000
Charge-offs	(16,643,000)		(7,774,000)		(8,554,000)
Recoveries	2,139,000		1,811,000		3,258,000
Net charge-offs	(14,504,000)		(5,963,000)		(5,296,000)
Balance, end of year	36,286,000	[2]	31,351,000	[1]	29,028,000	[1]
Loans individually evaluated for impairment	680,000		2,831,000
Loans collectively evaluated for impairment	35,606,000		28,520,000
Loans, Excluding Acquired Loans [Member] | Commercial Portfolio Segment [Member]
Balance, beginning of year	5,985,000	[1]	6,962,000	[1]	3,205,000
Provision for loan losses	5,345,000	[2]	258,000	[2]	4,475,000
Charge-offs	(3,956,000)		(1,415,000)		(1,044,000)
Recoveries	365,000		180,000		326,000
Net charge-offs	(3,591,000)		(1,235,000)		(718,000)
Balance, end of year	7,739,000	[2]	5,985,000	[1]	6,962,000	[1]
Loans individually evaluated for impairment	262,000		432,000
Loans collectively evaluated for impairment	7,477,000		5,553,000
Loans, Excluding Acquired Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Balance, beginning of year	19,522,000	[1]	15,161,000	[1]	16,885,000
Provision for loan losses	9,461,000	[2]	5,738,000	[2]	(606,000)
Charge-offs	(7,517,000)		(1,580,000)		(2,684,000)
Recoveries	351,000		203,000		1,566,000
Net charge-offs	(7,166,000)		(1,377,000)		(1,118,000)
Balance, end of year	21,817,000	[2]	19,522,000	[1]	15,161,000	[1]
Loans individually evaluated for impairment	417,000		2,307,000
Loans collectively evaluated for impairment	21,400,000		17,215,000
Loans, Excluding Acquired Loans [Member] | Consumer Portfolio Segment [Member]
Balance, beginning of year	3,893,000	[1]	5,445,000	[1]	5,430,000
Provision for loan losses	2,174,000	[2]	665,000	[2]	2,307,000
Charge-offs	(3,195,000)		(3,107,000)		(3,188,000)
Recoveries	907,000		890,000		896,000
Net charge-offs	(2,288,000)		(2,217,000)		(2,292,000)
Balance, end of year	3,779,000	[2]	3,893,000	[1]	5,445,000	[1]
Loans individually evaluated for impairment			7,000
Loans collectively evaluated for impairment	3,779,000		3,886,000
Loans, Excluding Acquired Loans [Member] | Unallocated Financing Receivables [Member]
Balance, beginning of year	1,951,000	[1]	1,460,000	[1]	1,922,000
Provision for loan losses	2,459,000	[2]	1,625,000	[2]	706,000
Charge-offs	(1,975,000)		(1,672,000)		(1,638,000)
Recoveries	516,000		538,000		470,000
Net charge-offs	(1,459,000)		(1,134,000)		(1,168,000)
Balance, end of year	2,951,000	[2]	1,951,000	[1]	$ 1,460,000	[1]
Loans individually evaluated for impairment	1,000		85,000
Loans collectively evaluated for impairment	$ 2,950,000		$ 1,866,000

[1] Allowance for loan losses at December 31, 2016, 2015 and 2014 includes $954,000 allowance for loans acquired (not shown in the table above). The total allowance for loan losses at December 31, 2016, 2015 and 2014 was $37,240,000, $32,305,000 and $29,982,000, respectively.

[2] Provision for loan losses of $626,000 attributable to loans acquired was excluded from this table for the year ended December 31, 2016 (total provision for loan losses for the year ended December 31, 2016 was $20,065,000). The $626,000 was subsequently charged-off, resulting in no increase to the ending balance in the allowance related to loans acquired. Provision for loan losses of $736,000 attributable to acquired loans, covered by FDIC loss share, was excluded from this table for the year ended December 31, 2015 (total provision for loan losses for the year ended December 31, 2015 is $9,022,000).