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Stock Based Compensation Narrative (Details) - plan | 12 Months Ended |  |  |
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Dec. 31, 2020 | Sep. 25, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |
Number of compensation plans | 3 |  |  |  |
Stock dividend, percent | 300.00% | [1] | 300.00% | 300.00% | 300.00%
Expiration period (in years) | 10 years |  |  |  |
Award vesting period (in years) | 4 years |  |  |  |
Discount from market price | 5.00% |  |  |  |
Restricted Stock Units (RSUs) |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |
Award vesting period (in years) | 3 years |  |  |  |
Employee Stock |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |
Discount from market price | 5.00% |  |  |  |
[1] | Included in the shares issued for the 3% stock dividend in 2020 were treasury shares of 137,041

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- Definition Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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