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Equity Compensation, Employment Agreements and Other Benefit Plans (Dividend Equivalents) (Details) - DER - USD ($) | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Payments attributable to DERs | $ 367,000 | $ 1,049,000 | $ 907,000
Dividend equivalent rights (in shares) | 0 | 0 |

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