Pension and Non-pension Post-employment Benefit Plans - Market Value of Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Employee Benefits [Abstract]
Debt investment funds	$ 10.2	$ 225.2
Equity investment funds	6.6	7.0
Insurance annuities	266.5	148.5
Other	9.7	14.8
Total	$ 293.0	$ 395.5
Debt investment funds, allocation percentage	4.00%	57.00%
Equity investment funds, allocation percentage	2.00%	2.00%
Insurance annuities, allocation percentage	91.00%	37.00%
Other, allocation percentage	3.00%	4.00%
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]

+ References

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- Definition

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

+ References

No definition available.

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- Definition

Insurance Annuities, Amount Contributed To Fair Value Of Plan Assets

+ References

No definition available.

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- Definition

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

+ References

No definition available.

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- Definition

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

+ References

No definition available.

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- Definition

Plan Assets At Fair Value, Allocation Percentage

+ References

No definition available.

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- Definition

The amount that instruments representing debt (rather than equity) constitute of 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 that instruments representing equity (rather than debt) constitute of 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 that other types of assets not separately disclosed constitute of 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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