Stock-Based Compensation - Assumptions Long-Term Awards (Details) - Long-Term Awards [Member] - $ / shares shares in Thousands |
9 Months Ended | 12 Months Ended | |
|---|---|---|---|
Sep. 30, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
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| 2020 Program [Member] | |||
| Fair value | $ 14.86 | ||
| Target awards | 76 | ||
| Volatility | 42.37% | ||
| Risk-free rate | 0.26% | ||
| Dividend assumption | reinvested | ||
| Expected term in years | 3 years | ||
| 2019 Program [Member] | |||
| Fair value | $ 13.47 | ||
| Target awards | 70 | ||
| Volatility | 28.75% | ||
| Risk-free rate | 0.72% | ||
| Dividend assumption | reinvested | ||
| Expected term in years | 3 years | ||
| 2018 Program [Member] | |||
| Fair value | $ 10.07 | ||
| Target awards | 82 | ||
| Volatility | 31.70% | ||
| Risk-free rate | 2.50% | ||
| Dividend assumption | reinvested | ||
| Expected term in years | 3 years | ||
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- Definition The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition If different dividend rates are used during the contractual term, then disclose the range of expected dividends used. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The risk-free interest rate assumption that is used in valuing an option on its own shares. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Number of shares purchased for issuance under share-based payment arrangement. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Price of a single share of a number of saleable stocks of a company. No definition available.
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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. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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