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Stock-based Employee Compensation, Stock Option Plans, and Deferred Compensation Plan for Directors - Stock Options Issued (Details) | 9 Months Ended
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Sep. 30, 2020 $ / shares
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |
Exercise price (in usd per share) | $ 49.19
Directors | May 3, 2019 |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |
Exercise price (in usd per share) | $ 55.71
Volatility | 0.236
Expected life (years) | 5 years
Assumed yield | 3.75%
Risk-free rate | 2.33%
Directors | April 24, 2020 |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |
Exercise price (in usd per share) | $ 50.00
Volatility | 0.258
Expected life (years) | 5 years
Assumed yield | 3.80%
Risk-free rate | 0.36%
Officers | May 3, 2019 |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |
Exercise price (in usd per share) | $ 55.71
Volatility | 0.206
Expected life (years) | 7 years
Assumed yield | 3.80%
Risk-free rate | 2.43%
Officers | April 24, 2020 |
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items] |
Exercise price (in usd per share) | $ 50.00
Volatility | 0.240
Expected life (years) | 7 years
Assumed yield | 3.85%
Risk-free rate | 0.51%

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- Definition The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term. + 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 (f)(2)(iii) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition The risk-free interest rate assumption that is used in valuing an option on its own shares. + 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 (f)(2)(iv) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition Weighted average price at which option holders acquired shares when converting their stock options into shares. + References No definition available. + Details
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- Definition Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + 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 (f)(2)(i) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.D.2) -URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809 + Details
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