Note 7 - Stock-based Compensation and Other Plans (Details Textual) - USD ($)	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Payment Arrangement, Option [Member]
Share-based Payment Arrangement, Expense	$ 42,000	$ 63,000	$ 112,000	$ 160,000
Share-based Payment Arrangement, Expense, Tax Benefit	11,000	16,000	28,000	40,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	75,000		75,000
Restricted Stock [Member]
Share-based Payment Arrangement, Expense	0	0	0	5,000
Share-based Payment Arrangement, Expense, Tax Benefit	0	$ 0	0	$ 1,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 0		$ 0
The 2018 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)			585,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance (in shares)	565,000		565,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)	0		0
The 2008 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)			3,044,927

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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

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Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

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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).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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