Employee Benefits - U.S. and Canadian Other Post-Retirement Benefits Narrative (Details) - Other Post-Retirement Benefits - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Unrecognized prior-service cost	$ 1.0	$ 1.0
Unrecognized loss	13.0	$ 3.0
Amounts in Accumulated other comprehensive income (loss) expected to be recognized as components of net periodic benefit cost in next fiscal year	0.2
Expected employer contributions during next fiscal year	5.0
Expected future benefit payments 2021	5.0
Expected future benefit payments 2026 – 2030	$ 26.0
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%
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%
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%