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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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Target allocation maximum percentage of investments of this type to total plan assets presented on a weighted average basis.

+ 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)(i)

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

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-Name Accounting Standards Codification

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Target allocation minimum percentage of investments of this type to total plan assets presented on a weighted average basis.

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 70

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6414718&loc=d3e28014-114942

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Employee Benefit Plans - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Defined contribution saving plan expense	$ 8.9	$ 7.8	$ 6.4
Pension Benefits, Domestic
Defined Benefit Plan Disclosure [Line Items]
Expected contribution for 2014	16.0
Postretirement Plans, Domestic
Defined Benefit Plan Disclosure [Line Items]
Expected contribution for 2014	0.5
Pension Benefits, Foreign
Defined Benefit Plan Disclosure [Line Items]
Expected contribution for 2014	$ 4.0
Equities
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation, minimum	25.00%	25.00%
Target asset allocation, maximum	40.00%	40.00%
Bonds
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation, minimum	20.00%	20.00%
Target asset allocation, maximum	40.00%	40.00%
Cash Alternatives Investments and Other
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation, minimum	25.00%	25.00%
Target asset allocation, maximum	45.00%	45.00%