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Employee Incentive Plans - Additional Information (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |
Shares available for awards (shares) | 312,601 |  |
Recognized tax benefit relating to non-cash compensation expense | $ 2.3 | $ 2.4 | $ 2.5
Share-based Compensation Arrangement by Share-based Payment Award, options, vested in period, fair value | $ 12.4 | $ 16.4 | $ 19.4
Restricted stock units (RSUs) |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |
Number of common share received by the employee on vesting | 1 |  |
Service period | 3 years |  |
Restricted Stock |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |
Service period | 1 year |  |
Performance Shares |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |
Number of common share received by the employee on vesting | 1 |  |
Performance Shares | Tranche One |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |
Performance period | 3 years |  |
Performance Shares | Tranche Two |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |
Performance period | 3 years |  |
Performance Shares | Tranche Three |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |
Performance period | 3 years |  |
Performance Shares | Tranche Four |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |
Performance period | 3 years |  |
Performance Shares | Minimum |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |
Number of performance shares that may be earned, as a percentage (percent) | 0.00% |  |
Performance Shares | Maximum |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |
Number of performance shares that may be earned, as a percentage (percent) | 200.00% |  |
Accrued salaries, wages and related expenses |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |
Accrued salaries, wages and related expenses | $ 5.2 |  |

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- Definition Carrying value as of the balance sheet date of obligations incurred and payable for incentive compensation awarded to employees and directors or earned by them based on the terms of one or more relevant arrangements. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.15(a)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.15(5)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 + Details
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- Definition Amount of tax benefit for recognition of expense of award under share-based payment arrangement. + 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 (h)(1)(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 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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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable. + 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 -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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