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Note 5 - Common Shares and Earnings Per Share - Reconciliation of Company's Common Shares (Details)	3 Months Ended
	Mar. 31, 2020 shares
Common Shares Outstanding, beginning balance (in shares)	40,157,591
Dividends Reinvested (in shares)	30,677
Cash Invested (in shares)	12,772
Vesting of Restricted Stock Units (in shares)	23,000
Cash Invested (in shares)	13,432
Dividends Reinvested (in shares)	2,316
Shares Withheld for Individual Income Tax Requirements (in shares)	(38,217)
Common Shares Outstanding, ending balance (in shares)	40,376,448
Performance Awards 2016 [Member]
Executive Stock Performance Awards (2017 awards earned) (in shares)	62,497
At the Market Offering [Member]
At-the-Market Offering (in shares)	112,380

X

- Definition

Represents the number of common shares withheld for individual income tax requirements during the period.

+ References

No definition available.

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X

- Definition

Number of shares issued as resulted of dividends reinvestment during the period from a employee stock purchase plan.

+ References

No definition available.

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X

- Definition

Represents the number of shares for cash invested under dividend reinvestment and share purchase plan.

+ References

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X

- Definition

Represents the number of restricted shares of common stock vested.

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- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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- Definition

Number of shares issued during the period from a dividend reinvestment plan (DRIP). A dividend reinvestment plan allows the shareholders to reinvest dividends paid to them by the entity on new issues of stock by the entity.

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Number of shares issued during the period as a result of an employee stock purchase plan.

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Number of new stock issued during the period.

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

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