Income Taxes - Allocation of Total Income Taxes (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Income Tax Disclosure [Abstract]
Income tax benefit on loss before income taxes	$ (290.2)	$ (158.3)
Income tax expense on discontinued operations	(2.8)	6.9
Accumulated other comprehensive loss	$ 1.5	$ 2.9

Tax effect allocated to a disposal group that is classified as a component of the entity reported as a separate component of income before extraordinary items. Includes the tax effects of the following: income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

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+ Details

- Definition

The sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to continuing operations.

+ References+ Details

- Definition

Tax effect of other comprehensive income (loss) attributable to both parent entity and noncontrolling interest.

+ References

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-Name Accounting Research Bulletin (ARB)

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+ Details