Pension and Non-pension Post-employment Benefit Plans - Market Value of Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Employee Benefits [Abstract]
Debt investment funds	$ 10.3	$ 10.2
Equity investment funds	7.4	6.6
Insurance annuities	299.8	266.5
Other	11.0	9.7
Total	$ 328.5	$ 293.0
Debt investment funds, allocation percentage	3.00%	4.00%
Equity investment funds, allocation percentage	2.00%	2.00%
Insurance annuities, allocation percentage	91.00%	91.00%
Other, allocation percentage	4.00%	3.00%
Total, allocation percentage	100.00%	100.00%

Debt Instruments, Amount Contributed To Fair Value Of Plan Assets, Allocation Percentage

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- Definition

Employee Benefits [Abstract]

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- Definition

Equity Instruments, Amount Contributed To Fair Value Of Plan Assets, Allocation Percentage

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- Definition

Insurance Annuities, Amount Contributed To Fair Value Of Plan Assets

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No definition available.

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- Definition

Insurance Annuities, Amount Contributed To Fair Value of Plan Assets, Allocation Percentage

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No definition available.

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- Definition

Other Assets, Amount Contributed To Fair Value Of Plan Assets, Allocation Percentage

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- Definition

Plan Assets At Fair Value, Allocation Percentage

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No definition available.

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- Definition

The amount instruments representing debt (rather than equity) contribute to the fair value of defined benefit plan assets. [Refer: Plan assets, at fair value; Defined benefit plans [member]]

+ References

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- Definition

The amount instruments representing equity (rather than debt) contribute to the fair value of defined benefit plan assets. [Refer: Plan assets, at fair value; Defined benefit plans [member]]

+ References

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- Definition

The amount other types of assets not separately disclosed contribute to the fair value of defined benefit plan assets. [Refer: Plan assets, at fair value; Defined benefit plans [member]]

+ References

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- Definition

The fair value of defined benefit plan assets. Plan assets comprise assets held by a long-term employee benefit fund and qualifying insurance policies. [Refer: At fair value [member]]

+ References

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