Employee Retirement Plans and Postretirement Benefits - Projected Benefit Obligation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Change in benefit obligation:
Prior year benefit obligation	$ 6,276.2	$ 5,871.1
Service cost, net of expected employee contributions	8.3	8.3
Interest cost	108.5	139.3
Actual employee contributions	0.4	0.4
Actuarial (gain) loss	(264.7)	504.0
Plan amendments	0.0	0.8
Benefits paid	(333.4)	(355.8)
Curtailment, settlement and special termination	(35.4)	(0.1)
Foreign currency exchange rate change	(15.4)	108.2
Benefit obligation at end of year	5,744.5	6,276.2	$ 5,871.1
Change in plan assets:
Prior year fair value of assets	5,958.4	5,542.1
Actual return on plan assets	55.5	614.0
Employer contributions	42.5	44.5
Curtailment, settlement and special termination	(35.4)	(0.2)
Benefits and plan expenses paid	(333.4)	(356.3)
Foreign currency exchange rate change	(20.5)	113.9
Fair value of plan assets at end of year	5,667.5	5,958.4	5,542.1
Funded status:	(77.0)	(317.8)
Amounts recognized in the Consolidated Balance Sheets:
Other non-current assets	622.9	492.8
Accounts payable and other current liabilities	(45.5)	(47.4)
Pension and postretirement benefits	(654.4)	(763.2)
Net amounts recognized	(77.0)	(317.8)
Amounts in Accumulated Other Comprehensive Loss (Income) not yet recognized as components of net periodic pension cost or (benefit), pre-tax:
Net actuarial (gain) loss	411.1	576.0
Net prior service (benefit) cost	6.9	6.5
Total not yet recognized	418.0	582.5	520.4
Pension
Change in benefit obligation:
Prior year benefit obligation	5,571.5	5,198.6
Service cost, net of expected employee contributions	2.3	2.3
Interest cost	93.9	120.5	161.9
Actual employee contributions	0.4	0.4
Actuarial (gain) loss	(227.4)	460.3
Plan amendments	0.0	0.8
Benefits paid	(293.1)	(316.6)
Curtailment, settlement and special termination	(35.4)	(0.1)
Foreign currency exchange rate change	(16.4)	105.3
Benefit obligation at end of year	5,095.8	5,571.5	5,198.6
Change in plan assets:
Prior year fair value of assets	5,958.4	5,542.1
Actual return on plan assets	55.5	614.0
Employer contributions	2.2	4.8
Curtailment, settlement and special termination	(35.4)	(0.2)
Benefits and plan expenses paid	(293.1)	(316.6)
Foreign currency exchange rate change	(20.5)	113.9
Fair value of plan assets at end of year	5,667.5	5,958.4	5,542.1
Funded status:	571.7	386.9
Amounts recognized in the Consolidated Balance Sheets:
Other non-current assets	622.9	492.8
Accounts payable and other current liabilities	(4.1)	(4.1)
Pension and postretirement benefits	(47.1)	(101.8)
Net amounts recognized	571.7	386.9
Funded status:
Accumulated benefit obligation	51.2	831.4
Projected benefit obligation	51.2	831.6
Fair value of plan assets	0.0	725.7
Amounts in Accumulated Other Comprehensive Loss (Income) not yet recognized as components of net periodic pension cost or (benefit), pre-tax:
Net actuarial (gain) loss	553.4	684.6
Net prior service (benefit) cost	10.1	10.5
Total not yet recognized	563.5	695.1	692.8
OPEB
Change in benefit obligation:
Prior year benefit obligation	704.7	672.5
Service cost, net of expected employee contributions	6.0	6.0
Interest cost	14.6	18.8	25.5
Actual employee contributions	0.0	0.0
Actuarial (gain) loss	(37.3)	43.7
Plan amendments	0.0	0.0
Benefits paid	(40.3)	(39.2)
Curtailment, settlement and special termination	0.0	0.0
Foreign currency exchange rate change	1.0	2.9
Benefit obligation at end of year	648.7	704.7	672.5
Change in plan assets:
Prior year fair value of assets	0.0	0.0
Actual return on plan assets	0.0	0.0
Employer contributions	40.3	39.7
Curtailment, settlement and special termination	0.0	0.0
Benefits and plan expenses paid	(40.3)	(39.7)
Foreign currency exchange rate change	0.0	0.0
Fair value of plan assets at end of year	0.0	0.0	0.0
Funded status:	(648.7)	(704.7)
Amounts recognized in the Consolidated Balance Sheets:
Other non-current assets	0.0	0.0
Accounts payable and other current liabilities	(41.4)	(43.3)
Pension and postretirement benefits	(607.3)	(661.4)
Net amounts recognized	(648.7)	(704.7)
Amounts in Accumulated Other Comprehensive Loss (Income) not yet recognized as components of net periodic pension cost or (benefit), pre-tax:
Net actuarial (gain) loss	(142.3)	(108.6)
Net prior service (benefit) cost	(3.2)	(4.0)
Total not yet recognized	$ (145.5)	$ (112.6)	$ (172.4)