Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2015	Mar. 31, 2015	Mar. 31, 2014
Income Tax Disclosure [Abstract]
Accrued interest on uncertain tax position	$ 0	$ 0	$ 4.4
Accrued penalities on uncertain tax position	0	0	3.2
Percentage of penalties and related interest assessed to date	40.00%
Impact from settlement agreement	17	17
Interest related to tax penalties	$ 4.4	$ 4.4

Percentage of penalties and related interest assessed to date.

No definition available.

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- Definition

Tax settlements, interest on penalties received.

+ References

No definition available.

+ Details

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- Details

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- Definition

The amount of the additional liability or refund received or expected based on a final settlement with a taxing authority.

+ 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 statutory penalties accrued for a tax position claimed or expected to be claimed by the entity, in its tax return.

+ References

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- Definition

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

+ References

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