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Shared-Based Payments (Summary of ESPP and ASPP Shares Issued) (Details) - shares | 12 Months Ended
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Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Schedule of Share-Based Compensation ESPP and ASPP Shares Granted [Line Items] |  |  |
Stock Issued During Period Shares | 613,678 | 540,337 | 635,521
Employee Stock [Member] |  |  |
Schedule of Share-Based Compensation ESPP and ASPP Shares Granted [Line Items] |  |  |
Stock Issued During Period Shares | 72,952 | 70,448 | 75,093
Agent Stock Purchase Plan [Member] |  |  |
Schedule of Share-Based Compensation ESPP and ASPP Shares Granted [Line Items] |  |  |
Stock Issued During Period Shares | 47,888 | 41,134 | 49,794

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