Retirement Benefits - Narrative (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2020 USD ($)	Dec. 31, 2021 USD ($) employee shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 employee
Defined Benefit Plan Disclosure [Line Items]
Actuarial loss (gain)		$ 9.7
Deferred pension cost (reversal of cost)		10.7
Plan assets, period increase (decrease)		1.0
Funded status		10.2
Accumulated benefit obligation for all defined benefit pension plans		$ 110.7	$ 204.4
Percentage of excess gains and losses over benefit obligation or market value of assets amortized		10.00%
Costs of defined contribution plans		$ 12.8	12.5	$ 12.4
Number of participants covering under multi employer pension plan | employee		212
Costs of bargaining unit-sponsored multi-employer plans and defined contribution plans		$ 1.0	1.1	1.1
Weighted average annual rate of increase in the per capita cost of covered health care benefits assumed		5.45%
Assumed decrease of weighted average health care cost trend rate		4.45%
Year that reaches assumed decrease of weighted average health care cost trend rate		2040
Stock held in plan assets (in shares) | shares		0
Estimated Future Benefit Payments
2022		$ 6.4
2023		6.0
2024		6.0
2025		6.3
2026		6.3
2027 to 2031		31.8
Other (Income) Expense Net
Defined Benefit Plan Disclosure [Line Items]
Settlement loss recognized	$ 0.9			0.7
Net periodic benefit cost			1.0
Defined Contribution Plan
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, expected contribution for next fiscal year		15.1
401k
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, expected contribution for next fiscal year		$ 10.2
U.S. | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation of fund assets in equities		10.00%
U.S. | Fixed Income Securities | Minimum
Defined Benefit Plan Disclosure [Line Items]
Target allocation of fund assets in equities		90.00%
UK | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation of fund assets in equities		62.00%
UK | Equity Securities | Minimum
Defined Benefit Plan Disclosure [Line Items]
Target allocation of fund assets in equities		60.00%
UK | Equity Securities | Maximum
Defined Benefit Plan Disclosure [Line Items]
Target allocation of fund assets in equities		65.00%
UK | Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation of fund assets in equities		38.00%
UK | Fixed Income Securities | Minimum
Defined Benefit Plan Disclosure [Line Items]
Target allocation of fund assets in equities		35.00%
UK | Fixed Income Securities | Maximum
Defined Benefit Plan Disclosure [Line Items]
Target allocation of fund assets in equities		40.00%
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Participants affected due to plan freeze | employee					60
Defined benefit plan, expected contribution for next fiscal year		$ 4.0
Pension Benefits | U.S.
Defined Benefit Plan Disclosure [Line Items]
Settlement loss recognized		10.5	0.9	0.7
Net periodic benefit cost		(10.4)	0.3	(2.7)
Actuarial loss (gain)		1.9	(6.5)
Funded status		6.4	6.0
Pension Benefits | Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Settlement loss recognized		0.0	(0.4)	0.0
Net periodic benefit cost		(3.8)	(3.4)	$ (3.4)
Actuarial loss (gain)		5.3	(7.3)
Funded status		$ (58.2)	(73.5)
Pension Benefits | UK
Defined Benefit Plan Disclosure [Line Items]
Target allocation of fund assets in equities		3.10%
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Actuarial loss (gain)		$ 0.8	(3.2)
Funded status		(23.6)	$ (24.2)
Defined benefit plan, expected contribution for next fiscal year		$ 1.2