Summary of Changes in Fair Value of Plans' Level 3 Assets (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014
U.S. Plans
Changes In Level 3 Assets And Liabilities Measured At Fair Value On Recurring Basis [Line Items]
Fair value of plan assets at beginning of year	$ 4,069.7	$ 4,048.0
Fair value of plan assets at end of year	3,759.4	4,069.7
Other Postretirement Benefit Plans
Changes In Level 3 Assets And Liabilities Measured At Fair Value On Recurring Basis [Line Items]
Fair value of plan assets at beginning of year	9.1	9.2
Fair value of plan assets at end of year	7.7	9.1
International Plans
Changes In Level 3 Assets And Liabilities Measured At Fair Value On Recurring Basis [Line Items]
Fair value of plan assets at beginning of year	2,718.9	2,681.8
Fair value of plan assets at end of year	2,496.8	2,718.9
Fair Value, Inputs, Level 3 \| U.S. Plans
Changes In Level 3 Assets And Liabilities Measured At Fair Value On Recurring Basis [Line Items]
Fair value of plan assets at beginning of year	64.4	130.7
Realized gains (losses)	(8.5)	(19.6)
Purchases or acquisitions	0.2
Sales or dispositions	(23.3)	(74.6)
Currency and unrealized gains (losses) relating to instruments still held at end of year	12.4	27.9
Fair value of plan assets at end of year	45.2	64.4
Fair Value, Inputs, Level 3 \| U.S. Plans \| Real Estate
Changes In Level 3 Assets And Liabilities Measured At Fair Value On Recurring Basis [Line Items]
Fair value of plan assets at beginning of year	34.2	34.7
Realized gains (losses)	0.1	4.7
Sales or dispositions	(0.1)	(4.9)
Currency and unrealized gains (losses) relating to instruments still held at end of year	3.4	(0.3)
Fair value of plan assets at end of year	37.6	34.2
Fair Value, Inputs, Level 3 \| U.S. Plans \| Private Equity
Changes In Level 3 Assets And Liabilities Measured At Fair Value On Recurring Basis [Line Items]
Fair value of plan assets at beginning of year	12.8	16.5
Realized gains (losses)	(8.2)	(24.4)
Purchases or acquisitions	0.2
Sales or dispositions	(6.6)	(6.7)
Currency and unrealized gains (losses) relating to instruments still held at end of year	9.4	27.4
Fair value of plan assets at end of year	7.6	12.8
Fair Value, Inputs, Level 3 \| U.S. Plans \| Insurance Contracts
Changes In Level 3 Assets And Liabilities Measured At Fair Value On Recurring Basis [Line Items]
Fair value of plan assets at beginning of year	17.4	79.5
Realized gains (losses)	(0.4)	0.1
Sales or dispositions	(16.6)	(63.0)
Currency and unrealized gains (losses) relating to instruments still held at end of year	(0.4)	0.8
Fair value of plan assets at end of year		17.4
Fair Value, Inputs, Level 3 \| Other Postretirement Benefit Plans \| Insurance Contracts
Changes In Level 3 Assets And Liabilities Measured At Fair Value On Recurring Basis [Line Items]
Fair value of plan assets at beginning of year	7.3	7.5
Realized gains (losses)	(0.1)
Purchases or acquisitions	0.5	0.2
Sales or dispositions		(0.4)
Fair value of plan assets at end of year	7.7	7.3
Fair Value, Inputs, Level 3 \| International Plans
Changes In Level 3 Assets And Liabilities Measured At Fair Value On Recurring Basis [Line Items]
Fair value of plan assets at beginning of year	227.0	244.3
Realized gains (losses)	0.2	(0.1)
Purchases or acquisitions	38.5	23.3
Sales or dispositions	(17.2)	(28.8)
Currency and unrealized gains (losses) relating to instruments still held at end of year	(15.8)	(11.7)
Fair value of plan assets at end of year	232.7	227.0
Fair Value, Inputs, Level 3 \| International Plans \| Real Estate
Changes In Level 3 Assets And Liabilities Measured At Fair Value On Recurring Basis [Line Items]
Fair value of plan assets at beginning of year	40.8	42.8
Realized gains (losses)	0.2	(0.2)
Purchases or acquisitions	6.1	15.3
Sales or dispositions	(5.9)	(15.5)
Currency and unrealized gains (losses) relating to instruments still held at end of year	0.6	(1.6)
Fair value of plan assets at end of year	41.8	40.8
Fair Value, Inputs, Level 3 \| International Plans \| Commingled Funds
Changes In Level 3 Assets And Liabilities Measured At Fair Value On Recurring Basis [Line Items]
Fair value of plan assets at beginning of year	50.7	50.2
Realized gains (losses)		0.1
Purchases or acquisitions	23.0	1.0
Sales or dispositions	(0.4)	(0.3)
Currency and unrealized gains (losses) relating to instruments still held at end of year	(3.0)	(0.3)
Fair value of plan assets at end of year	70.3	50.7
Fair Value, Inputs, Level 3 \| International Plans \| Insurance Contracts
Changes In Level 3 Assets And Liabilities Measured At Fair Value On Recurring Basis [Line Items]
Fair value of plan assets at beginning of year	135.5	151.3
Purchases or acquisitions	9.4	7.0
Sales or dispositions	(10.9)	(13.0)
Currency and unrealized gains (losses) relating to instruments still held at end of year	(13.4)	(9.8)
Fair value of plan assets at end of year	$ 120.6	$ 135.5

Changes In Level 3 Assets And Liabilities Measured At Fair Value On Recurring Basis [Line Items]

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- Definition

Actual return on plan assets, separately identifying the amount related to assets sold during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(iv)(02)(A)
-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)(iv)(02)(A)
-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e2446-114920

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Actual return on plan assets, separately identifying the amount related to assets still held at the reporting date.

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- Definition

The amount of increase in the plan assets attributed to a business combination.

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The amount of decrease in the plan assets attributed to the sale, liquidation, spin-off or other divestiture of a corporate division or subsidiary.

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 30
-Section 35
-Paragraph 50
-URI http://asc.fasb.org/extlink&oid=49178875&loc=d3e12355-114930

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-Name Accounting Standards Codification
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-Section 50
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

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