Retirement Plans and Other Post-Retirement Benefits - Schedule of Change in Benefit Obligation and Plan Assets (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Change in Benefit Obligation
Balance at end of year	$ 41.7	$ 35.4
Change in Plan Assets
Fair value of plan assets at end of year	0	0
Pension Benefits [Member]
Change in Benefit Obligation
Balance at beginning of year	487.7	528.4
Service cost	10.4	11.6	11.3
Interest cost	24.8	21.8	23.0
Plan amendments	3.6
Actuarial (gain)/loss	83.9	(44.0)
Benefits paid	(31.5)	(30.5)
Effect of currency rate changes	(1.3)	0.4
Balance at end of year	577.6	487.7	528.4
Change in Plan Assets
Fair value of plan assets at beginning of year	601.2	545.7
Actual return on plan assets	66.3	84.2
Total contributions	2.0	1.8
Benefits paid	(31.5)	(30.5)
Fair value of plan assets at end of year	638.0	601.2	545.7
Funded status at end of year	60.4	113.5
Other Benefits [Member]
Change in Benefit Obligation
Balance at beginning of year	54.8	63.0
Service cost	1.5	2.9	2.8
Interest cost	2.5	2.1	2.4
Participant contributions	1.3	1.4
Actuarial (gain)/loss	4.5	(10.5)
Benefits paid	(4.8)	(4.1)
Balance at end of year	59.8	54.8	63.0
Change in Plan Assets
Total contributions	4.8	4.1
Benefits paid	(4.8)	(4.1)
Funded status at end of year	$ (59.8)	$ (54.8)

The difference between fair value of plan assets at the end of the period and the fair value at the beginning of the period, adjusted for contributions and payments of benefits during the period, and after adjusting for taxes and other expenses, as applicable.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Actual Return on Plan Assets (Component of Net Periodic Postretirement Benefit Cost)

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Amount of gain (loss) related to change in benefit obligation resulting from changes in actuarial assumptions, for example, but not limited to, interest, mortality, employee turnover, salary, and temporary deviation from the substantive plan.

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1) For defined benefit pension plans, the benefit obligation is the projected benefit obligation, which is the actuarial present value as of a date of all benefits attributed by the pension benefit formula to employee service rendered prior to that date. 2) For other postretirement defined benefit plans, the benefit obligation is the accumulated postretirement benefit obligation, which is the actuarial present value of benefits attributed to employee service rendered to a particular date.

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The amount of payments made for which participants are entitled under a pension plan, including pension benefits, death benefits, and benefits due on termination of employment. Also includes payments made under a postretirement benefit plan, including prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. This item represents a periodic decrease to the plan obligations and a decrease to plan assets.

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The increase in the fair value of plan assets from contributions made by the employer.

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The amount of contributions made by plan participants. This item represents a periodic increase to the plan obligation and an increase to plan assets.

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Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets.

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Amount of gain (loss) from foreign currency exchange rate changes for benefit obligation for plans of a foreign operation whose functional currency is not the reporting currency.

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The funded status is measured as the difference between the fair value of plan assets and the benefit obligation. Will normally be the same as the net Defined Benefit Plan, Amounts Recognized in Balance Sheet, Total.

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The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time.

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The amount of increase or decrease due to a change in the terms of an existing plan or the initiation of a new plan. A plan amendment may increase or decrease benefits, including those attributed to years of service already rendered.

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The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan.

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