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Benefit Plans and Collective Bargaining Agreements - Non-Union Employees Narrative (Details) - 401(k) Employee Stock Ownership Plan - USD ($) | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019
Defined Contribution Plan Disclosure [Line Items] |  |
Employee maximum contribution percentage | 100.00% |
Employee maximum contribution amount | $ 19,500 |
Minimum age to qualify under Economic Growth and Tax Relief Reconciliation Act | 50 years |
Employee additional contribution eligible under economic growth and tax relief reconciliation act | $ 6,500 |
Employee maximum contribution eligible under economic growth and tax relief reconciliation act | $ 26,000 |
Employer maximum contribution percentage match | 100.00% | 100.00%
Matching percentage by employer of employees' gross pay | 4.00% | 4.00%
Matching contributions made by employer | $ 400,000 | $ 800,000
Employer discretionary contribution | $ 0 | $ 0

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- Definition Defined Contribution Plan, Maximum Annual Contribution Per Employee, Amount Under Economic Growth and Tax Relief Reconciliation Act + 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 Amount of discretionary contributions made by an employer to a defined contribution plan. + References No definition available. + Details
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- Definition Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan. + References No definition available. + Details
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- Definition Maximum amount the employee may contribute to a defined contribution plan. + References No definition available. + Details
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