Activity for Level Three Pension Plan Assets (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Benefits, Domestic
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year			$ 256.5
Fair value of plan assets at end of year	268.5	270.0	256.5
Pension Benefits, Domestic \| Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	13.8	14.1
Relating to assets held at year-end	0.7	(0.2)
Relating to assets sold during the period	0.2
Purchases, sales, settlements and other, net	(3.4)	(0.1)
Fair value of plan assets at end of year	11.3	13.8
Pension Benefits, Foreign
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year			33.5
Fair value of plan assets at end of year	35.0	35.7	33.5
Pension Benefits, Foreign \| Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	17.3	16.2
Relating to assets held at year-end	0.4	0.5
Purchases, sales, settlements and other, net	(2.2)	0.6
Fair value of plan assets at end of year	$ 15.5	$ 17.3

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

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=35743120&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=35743120&loc=d3e2446-114920

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- Definition

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

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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 20

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

Reference 2: 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=29635418&loc=d3e12355-114930

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- Definition

Amount of increase (decrease) in plan assets from purchases, sales and settlement of plan obligations.

+ 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)(B)

-URI http://asc.fasb.org/extlink&oid=35743120&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

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