Summary Of Interest Expense (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Debt Instruments [Abstract]
Interest incurred	$ 294.6us-gaap_InterestCostsIncurred	$ 276.0us-gaap_InterestCostsIncurred	$ 271.1us-gaap_InterestCostsIncurred
Less: interest income	(8.9)us-gaap_InterestIncomeOperating	(11.5)us-gaap_InterestIncomeOperating	(15.2)us-gaap_InterestIncomeOperating
Less: interest capitalized as property, plant and equipment	(3.6)	(3.1)	(4.1)
Interest expense, net	$ 282.1us-gaap_InterestExpense	$ 261.4us-gaap_InterestExpense	$ 251.8us-gaap_InterestExpense

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Amount of interest costs capitalized disclosed as an adjusting item to interest costs incurred.

+ References

No definition available.

+ Details

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- Definition

Total interest costs incurred during the period and either capitalized or charged against earnings.

+ References

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- Definition

Amount of the cost of borrowed funds accounted for as interest expense.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.9)

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 9

-Article 9

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- Definition

Amount of operating interest income, including, but not limited to, amortization and accretion of premiums and discounts on securities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1(e))

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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