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v3.20.4

Employee Benefit Plans - Defined Contribution Retirement Plans (Details) - USD ($) shares in Thousands, $ in Millions | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
The DC Plan |  |  |
Defined Contribution Retirement Plans |  |  |
Maximum voluntary contribution by eligible U.S. employees as a percentage of their compensation | 50.00% |  |
Number of shares contributed | 276 | 287 | 279
Compensation expense | $ 11.3 | $ 10.3 | $ 9.4
Supplemental Retirement Savings Plan (SRSP) |  |  |
Defined Contribution Retirement Plans |  |  |
Compensation expense | 0.2 | 0.2 | $ 0.3
Supplemental Retirement Savings Plan (SRSP) | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Contribution Retirement Plans |  |  |
Fair value of assets | $ 20.9 | $ 20.4 |

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- Definition Defined Contribution Plan, Fair Value of Plan Assets + References No definition available. + Details
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- Definition Represents the number of shares contributed by the entity under the defined contribution plan. + References No definition available. + Details
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- Definition Amount of cost for defined contribution plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 70 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942 + 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 Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan. + References No definition available. + Details
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- Details
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