Note 11 - Stock-based Compensation Plans (Details Textual) - USD ($)	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014
The 2008 Plan [Member] \| I S O Granted To Greater Than10 Percent Stockholders [Member]
Share Based Compensation Arrangement By Share Based Payment Award Options Term	5 years
The 2008 Plan [Member] \| Restricted Stock [Member] \| Employees and a Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	44,000
The 2008 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award Options Term	10 years
Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Percent	10.00%
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	5,600,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	1,200,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	$ 46,000	$ 445,000
Employee Service Share-based Compensation, Tax Benefit Realized from Exercise of Stock Options	17,500	169,000
Allocated Share-based Compensation Expense	395,000	511,000
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	150,000	197,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 516,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	1 year 219 days
ESP Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award Purchase Price of Common Stock Discount Rate	15.00%
CSP Plan [Member]
Affiliate Purchase Price of Common Stock Percent	15.00%
Restricted Stock [Member] \| Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	74,100
Restricted Stock [Member]
Allocated Share-based Compensation Expense	$ 39,000	144,000
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	15,000	$ 55,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 246,300
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	4 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	118,100	107,400
Earnings Before Interest, Taxes, Depreciation and Amortization	$ 8,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value	$ 155,200	$ 162,400
Share Based Compensation Arrangement By Share Based Payment Award Options Term	10 years
Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Percent	25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	$ 46,000	445,000
Allocated Share-based Compensation Expense	$ 434,000	$ 655,000

Represents information about the purchase price of common stock for affiliate expressed as a percentage of its value.

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The amount of earnings before interest, taxes, depreciation and amortization.

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Represents information about the discount for employee purchases of Common Stock.

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 14.F)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

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Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 14
-Section F

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Unrecognized cost of unvested share-based compensation awards.

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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Disclosure of the aggregate tax benefit realized from the exercise of stock options and the conversion of similar instruments during the annual period.

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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