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Employee Benefit Plans and Other Postretirement Benefits - Additional Information (Details) - USD ($) shares in Millions, $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) (Pre-Tax): |  |  |
Accumulated benefit obligation for plans with obligations in excess of plan assets | $ 1,400.0 |  |
Weighted-Average expected return on plan assets for 2021 | 4.91% |  |
Pension Contributions [Abstract] |  |  |
Company's common stock | 1.2 | 1.5 |
Deferred compensation liability | $ 22.6 | $ 17.4 |
Minimum |  |  |
Pension Contributions [Abstract] |  |  |
Company's contribution to pension plan, percentage | 3.00% |  |
Maximum |  |  |
Pension Contributions [Abstract] |  |  |
Company's contribution to pension plan, percentage | 5.00% |  |
Pension Plans |  |  |
Amounts Recognized in Accumulated Other Comprehensive Loss (Income) (Pre-Tax): |  |  |
Weighted-Average expected return on plan assets for 2021 | 5.29% | 6.06% | 6.06%
Pension Contributions [Abstract] |  |  |
Contributions to pension plan | $ 83.7 | $ 58.9 |
Pension Plans | Qualified Plan |  |  |
Pension Contributions [Abstract] |  |  |
Contributions to pension plan | 82.5 | 57.9 | $ 21.8
Matching Contributions |  |  |
Pension Contributions [Abstract] |  |  |
Company's contribution to defined contribution plans | 40.8 | 39.0 | 36.8
Service Related Contributions |  |  |
Pension Contributions [Abstract] |  |  |
Company's contribution to defined contribution plans | $ 39.4 | $ 36.7 | $ 33.3

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- Definition Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(3) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e2919-114920 + Details
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