Employee Plans - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of unissued common stock available for grant under the plans	2,300,000
Age requirement for vesting provision, minimum	55 years
Completion of service period (in years) for stock awards	5 years
Maximum contractual term of options granted (in years)	7 years	5 years
Option vesting period (in years)	3 years
Share-based compensation expense	$ 9.4	$ 10.4	$ 12.5
Proceeds from exercise of stock options	3.7	3.4	4.9
Deferred compensation Liability	12.6	12.1
Recognized net actuarial loss	(196.3)
Amortization of prior service (credit)	(4.3)
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	4.7	7.1	9.3
Total intrinsic value of options exercised	0.6	4.7	7.9
Total unrecognized compensation cost	$ 4.0
Unrecognized compensation cost, Weighted-average recognition period	1 year 10 months 24 days
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 4.7	3.3	3.2
Total unrecognized compensation cost	$ 4.9
Unrecognized compensation cost, Weighted-average recognition period	2 years 1 month 6 days
Aggregate weighted-average grant-date fair value of units granted	$ 10.2	12.8	5.3
Aggregate weighted-average grant-date fair value of units vested	$ 2.1	3.3	4.5
Performance-Based Unit \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares which will vest after achievement of goals	0
Performance-Based Unit \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares which will vest after achievement of goals	2.0
Other Postretirement Benefit Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected pretax amortization of net loss in 2016	$ (1.1)
Expected pretax amortization of prior service cost in 2016	0.1
Recognized net actuarial loss	(1.8)	(1.7)	(4.5)
Amortization of prior service (credit)	1.1	1.7	1.8
Estimated cash contributions by the company in 2016	$ 15.0
Pension Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Matching contribution by the company as percentage of participants' contribution	50.00%
Percentage of eligible pay contributed by participants that will be matched	6.00%
Cost recognized for contribution plans	$ 9.9	10.6	11.8
Expected pretax amortization of net loss in 2016	(155.7)
Expected pretax amortization of prior service cost in 2016	(5.7)
Estimated cash contributions by the company in 2016	139.3
International Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cost recognized for contribution plans	21.4	25.2	26.7
Recognized net actuarial loss	(63.6)	(40.2)	(51.9)
Amortization of prior service (credit)	(1.9)	(2.1)	(2.1)
Estimated cash contributions by the company in 2016	86.8
U.S. Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized net actuarial loss	(132.7)	(109.7)	(139.0)
Amortization of prior service (credit)	(2.4)	$ (0.4)	$ 0.7
Estimated cash contributions by the company in 2016	$ 52.5

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Matching Contribution By Employer As Percentage Of Participants Contribution

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Share Based Compensation Arrangement By Share Based Payment Award Contractual Term

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Share-based compensation arrangement by share-based payment award, other than options, grants in period, weighted average grant date fair value.

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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The carrying amount of the liability as of the balance sheet date to an individual under a deferred compensation arrangement. This amount may be the result of periodic accruals made over the period of active employment, or reflect termination benefits resulting contractual terms or a death benefit.

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The amount of the prior service cost or credit recognized in net periodic benefit cost relating to benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation.

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Amount of employer's best estimate of contributions expected to be paid to the plan during the next fiscal year beginning after the date of the latest statement of financial position.

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The amount of the cost recognized during the period for defined contribution plans.

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Unrecognized cost of unvested share-based compensation awards.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The cash inflow associated with the amount received from holders exercising their stock options. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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