Number of options each director received at each annual meeting.

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Options vesting percentage on first and second anniversary.

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Sharebased compensation arrangement by sharebased payment award number of options ungranted.

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Represents the stock to be granted per recipient under the share-based compensation arrangement.

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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Number of shares authorized for issuance under share-based payment arrangement.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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Net number of share options (or share units) granted during the period.

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Gross number of share options (or share units) granted during the period.

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Number of fully vested and expected to vest options outstanding that can be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Number of share options (or share units) exercised during the current period.

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Value, after forfeiture, of shares issued under share-based payment arrangement. Excludes employee stock ownership plan (ESOP).

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Note 10 - Stock Compensation Plans (Details Textual) - USD ($)	1 Months Ended	4 Months Ended	12 Months Ended			216 Months Ended
	Aug. 31, 2000	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2015	Dec. 31, 2020	Aug. 31, 2020	Jun. 30, 2015	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)				107,000		947,320
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)				42,000		1,356,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Total (in shares)				16,000		282,680
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number (in shares)		102,500	102,500	84,500		102,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number (in shares)		24,000	24,000			24,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term (Year)			10 years	10 years
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total		$ 235,000	$ 235,000			$ 235,000
Minimum [Member] \| Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)			2 years
Maximum [Member] \| Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)			3 years
The 2003 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)					450,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)					3 years
Sharebased Compensation Arrangement By Sharebased Payment Award Number Of Options Ungranted (in shares)									197,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)			0	25,000
The 2015 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)								750,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)			0	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)			0	30,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Total (in shares)				10,000
The Directors Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)	200,000
Sharebased Compensation Arrangement By Sharebased Payment Award Number Of Options Ungranted (in shares)	60,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)			0	8,000
Number Of Options Each Director Received At Each Annual Meeting (in shares)	4,000
Options Vesting Percentage On First And Second Anniversary	50.00%
The Directors Plan [Member] \| Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)	5,000
The 2011 Non-employee Director Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)							200,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)			0	74,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)			0	12,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Total (in shares)			0	6,000
Three Independent Members of the Board of Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures, Total (in shares)			4,380
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture, Total			$ 150,000
Share-Based Compensation Arrangement, Stock to be Granted Per Recipient, Value		$ 50,000