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Share-Based Compensation - Performance Restricted Stock Units Narrative (Details) - PRSUs shares in Thousands, $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2021 USD ($) metric shares | Dec. 31, 2020 USD ($) metric shares | Dec. 31, 2019 USD ($) shares | Dec. 31, 2018 shares
Share-based compensation |  |  |  |
Number of metrics | metric |  | 4 |  |
Number of restricted stocks units granted (in shares) | 189 | 292 | 190 |
Net reduction in number of awards with performance against target (in shares) | 56 | 99 | 106 |
Increase in number of awards against target performance (in shares) |  |  | 1 |
Reduction in number of awards with performance below target (in shares) |  |  | 103 |
Unvested restricted stock units outstanding (in shares) | 388 | 333 | 260 | 277
Fiscal 2019 Grants |  |  |  |
Share-based compensation |  |  |  |
Unvested restricted stock units outstanding (in shares) |  |  | 29 |
Accrued Expenses and Other Current Liabilities |  |  |  |
Share-based compensation |  |  |  |
Aggregate liability related to performance shares outstanding (less than) | $ |  |  | $ 100 |
Executive and senior officers |  |  |  |
Share-based compensation |  |  |  |
Performance payout period | 1 year |  |  |
Number of metrics | metric | 3 |  |  |
Requisite service period | 5 years |  |  |
Recognized share-based compensation expense | $ | $ 1,400 | $ 1,200 | 1,300 |
Unrecognized compensation cost, net of estimated forfeitures, related to restricted stock unit awards | $ | $ 2,000 |  |  |
Weighted-average period over which unrecognized compensation cost is expected to be recognized | 2 years 2 months 12 days |  |  |
Income tax benefit recognized on share-based compensation | $ | $ 1,400 | $ 600 | $ 2,100 |
Executive Officer |  |  |  |
Share-based compensation |  |  |  |
Performance payout period | 1 year |  |  |
Average share price trading period | 20 days | 20 days |  |
Share price, last day in trading period | 20 days | 20 days |  |
Dividend yield | 0.00% |  |  |

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- Definition Weighted-average period over which cost not yet recognized is expected to be recognized for 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 (i) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the 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 (a)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + 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 (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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