Income Taxes - Summary of Information Related to Interest and Penalties on Uncertain Tax Positions (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Interest expense (income)	$ 0.1	$ (0.2)
Penalties
Accrued interest payable	$ 0.7		$ 0.6

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The amount of estimated interest recognized in the period arising from income tax examinations.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319

+ Details

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- Definition

Amount of expense for penalties related to a tax position claimed or expected to be claimed in the tax return.

+ References

+ Details

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- Definition

Amount of interest expense accrued for an underpayment of income taxes.

+ References

+ Details

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