| **Stockholders’ Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands** | 12 Months Ended |             |
|----------------------------------------------------------------------------------------------------|-----------------|-------------|
||
| **Equity, Class of Treasury Stock [Line Items]**                                                   |            |        |   |   |
| Common stock, authorized                                                                           | 300,000,000     | 300,000,000 |   |   |
| Common stock, par value                                                                            | $ 0.50          | $ 0.50      |   |   |
| Preferred stock, shares authorized                                                                 | 1,770,819       |        |   |   |
| Preferred stock, par value                                                                         | $ 1.00          |        |   |   |
| Common and preferred shares authorized                                                             |            |        |   | $ 500,000 |
| Direct Stock Purchase Plan discount from current market value                                      | 5.00%           |        |   |   |
| Stock issued for acquisition, shares                                                               |            |        | 439,943 |   |
| Stock issued for acquisition                                                                       |            |        | $ 12,845 |   |
| Shares available for issuance under acquisition shelf registration                                 | $ 487,155       |        |   |   |
| Dividend Reinvestment [Member]                                                                     |            |        |   |   |
| **Equity, Class of Treasury Stock [Line Items]**                                                   |            |        |   |   |
| Shares purchased by transfer agent for dividend reinvestment plan                                  | 321,585         | 447,753     | 484,645 |   |
| Value of shares purchased in open market for dividend investment plan                              | $ 11,343        | $ 15,168    | $ 14,916 |   |
| Issue of common shares under dividend reinvestment plan                                            | 158,205         | 45,121      |   |   |
| Common stock sold under dividend reinvestment plan                                                 | $ 5,163         | $ 1,453     |   |   |

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Face amount or stated value per share of common stock.
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The maximum number of common shares permitted to be issued by an entity's charter and bylaws.
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
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Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.
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The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.
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Discount rate from fair value on purchase date that participants pay for shares.
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Number of shares of stock issued during the period pursuant to acquisitions.
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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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Value of stock issued pursuant to acquisitions during the period.
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Value of stock issued during the period from a dividend reinvestment plan (DRIP). A dividend reinvestment plan allows the holder of the stock to reinvest dividends paid to them by the entity on new issues of stock by the entity.
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