Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets
Pension liabilities	$ 53.1	$ 85.3
Retirement benefits other than pensions	54.6	67.5
Lease liabilities	85.4	72.3
Workers’ compensation and other claims	35.5	35.6
Property and equipment, net	35.7	39.2
Other assets and liabilities	94.2	108.7
Net operating loss carryforwards	72.8	74.8
Foreign tax and other tax credits(a)	82.8	81.6
Subtotal	514.1	565.0
Valuation allowances	(141.5)	(128.1)	$ (118.3)	$ (100.7)
Total deferred tax assets	372.6	436.9
Deferred tax liabilities
Right-of-use assets, net	76.9	68.3
Goodwill and other intangibles	76.7	60.0
Other assets and miscellaneous	28.8	36.4
Deferred tax liabilities	182.4	164.7
Net deferred tax asset	190.2	272.2
Noncurrent assets	239.4	314.9
Noncurrent liabilities	(49.2)	$ (42.7)
Operating Loss Carryforwards [Line Items]
Foreign tax credit amount	78.6
Remaining credits	4.2
Foreign
Deferred tax assets
Net operating loss carryforwards	$ 49.8
Operating Loss Carryforwards [Line Items]
Carryforward period (in years)	10 years