Note 11 - Employee Benefit Plans (Details Textual) - USD ($)	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Contribution Plan, Cost Recognized	$ 406,842	$ 369,969	$ 295,683
Deferred Compensation Arrangement with Individual, Compensation Expense	225,786	175,232	$ 165,222
Deferred Compensation Liability, Current and Noncurrent	$ 1,338,306	$ 1,282,087
First 3 Percent of Plan Compensation [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	100.00%
Matched at 100 Percent [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	3.00%
Between 3 Percent and 5 Percent of Plan Compensation [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	50.00%
Minimum [Member]
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	1.00%	1.00%	1.00%
Minimum [Member] \| Matched at 50 Percent [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	3.00%
Maximum [Member]
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	100.00%	100.00%	100.00%
Deferred Compensation Arrangement with Individual, Requisite Service Period	10 years
Maximum [Member] \| Matched at 50 Percent [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	5.00%

The compensation expense recognized during the period pertaining to the deferred compensation arrangement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 30
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6409875&loc=d3e20015-108363

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- Definition

Minimum period the individual is required to perform services to be fully vested under the deferred compensation arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 55
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6409961&loc=d3e20487-108367

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements. Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

+ References

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- Definition

The amount of the cost recognized during the period for defined contribution plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

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- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

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Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

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