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Employee Benefits - U.S. and Canadian Other Post-Retirement Benefits Narrative (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2019 | Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Expected future benefit payments 2024 | $ 5.0 |
Other Post-Retirement Benefits |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Unrecognized prior-service cost | 1.0 | $ 1.0
Unrecognized loss | 3.0 | $ (6.0)
Amounts in Accumulated other comprehensive income (loss) expected to be recognized as components of net periodic benefit cost in next fiscal year | 0.8 |
Expected employer contributions during next fiscal year | 4.0 |
Expected future benefit payments 2020 | 5.0 |
Expected future benefit payments 2021 | 5.0 |
Expected future benefit payments 2022 | 5.0 |
Expected future benefit payments 2023 | 5.0 |
Expected future benefit payments 2025-2029 | 25.0 |
Effect of one percentage point increase on accumulated postretirement benefit obligation | 3.0 |
Effect of one percentage point decrease on accumulated postretirement benefit obligation | 2.0 |
Effect of one percentage point increase on service cost and interest cost components of net periodic benefit cost | 0.1 |
Effect of one percentage point decrease on service cost and interest cost components of net periodic benefit cost | $ 0.1 |
Maximum percentage of liability for future plan cost increases for pre-65 and medical supplement plan coverage | 5.00% |
Maximum percentage of medical supplement plan into future periods | 5.00% |
Other Post-Retirement Benefits | Maximum |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Maximum percentage of liability for future plan cost increases for pre-65 and medical supplement plan coverage | 7.00% |
Other Post-Retirement Benefits | Minimum |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Maximum percentage of liability for future plan cost increases for pre-65 and medical supplement plan coverage | 4.00% |

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