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Shareholders' Equity (Changes in Shares of Common Stock) (Details) - shares	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Shareholders Equity [Line Items]
Treasury stock, beginning balance	57,630
Shares issued, beginning balance	16,099,556	16,099,556	16,099,556
Treasury stock purchases	238,439		0
Treasury stock, ending balance	270,657		57,630
Shares issued, ending balance	16,099,556	16,099,556	16,099,556
Common Stock [Member]
Shareholders Equity [Line Items]
Shares outstanding, beginning balance	16,041,926	16,002,899	16,002,899
Shares issued for Landmark Group acquisition	12,831
Restricted stock units released	18,819	22,921
Treasury stock purchases	(244,677)	(6,436)
Shares outstanding, ending balance	15,828,899	16,019,384	16,041,926
Treasury Stock [Member]
Shareholders Equity [Line Items]
Treasury stock, beginning balance	57,630	96,657	96,657
Shares issued for Landmark Group acquisition	(12,831)
Restricted stock units released	(18,819)	(22,921)
Treasury stock purchases	244,677	6,436
Treasury stock, ending balance	270,657	80,172	57,630

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Stock released during period shares restricted stock units.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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

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Number of shares of stock issued during the period pursuant to acquisitions.

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Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

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