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Benefit Plans - Narrative (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items] |  |  |
401 (k) plan contributions | $ 16,800,000 | $ 15,600,000 | $ 6,500,000
Employer contribution | 0 | 2,600,000 |
Fair value of plan assets | 258,100,000 | 244,100,000 |
Accumulated benefit obligation | 293,900,000 | 283,900,000 |
Expected contribution to the plan | $ 3,600,000 |  |
Assumed healthcare cost trend rate, benefit obligation | 6.50% |  |
Ultimate healthcare cost trend rate, benefit obligation | 5.00% |  |
Assumed healthcare cost trend rate, net periodic benefit cost | 6.25% |  |
Ultimate healthcare cost trend rate, net periodic benefit cost | 5.00% |  |
Other Nonoperating Income (Expense) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Settlements | $ 3,700,000 | $ 3,500,000 |
United States |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Discount rate | 2.60% | 3.35% |
Rate of compensation increase |  |  | 4.25%
Percentage of global plan assets | 83.00% |  |
Expected long-term rate of return on assets | 5.10% | 5.60% | 7.00%
International plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | $ 43,900,000 | $ 39,400,000 |
Accumulated benefit obligation | 83,100,000 | $ 73,900,000 |
Expected contribution to the plan | $ 2,900,000 |  |
Discount rate | 0.89% | 1.28% |
Rate of compensation increase | 2.58% | 2.49% |
Pension benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Settlements | $ (3,700,000) | $ (3,500,000) | $ 0
Fair value of plan assets | $ 258,100,000 | $ 244,100,000 | $ 214,500,000
Discount rate | 2.10% | 2.79% |
Rate of compensation increase | 2.58% | 2.49% |
Expected long-term rate of return on assets | 5.10% | 5.54% | 6.71%
Other retirement benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Settlements | $ 0 | $ 0 | $ 0
Fair value of plan assets | 0 | $ 0 | $ 0
Expected contribution to the plan | $ 700,000 |  |
Discount rate | 2.30% | 4.20% |

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- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation 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)(1) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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- Definition Weighted average rate increase of compensation, used to determine benefit obligation of defined benefit plan. Plan includes, but is not limited to, pay-related 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)(2) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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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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