v2.4.0.8

Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Income Tax [Line Items]
Effective tax benefit rate	41.80%	23.80%	68.90%	19.30%
U.S. federal statutory rate	35.00%	35.00%	35.00%	35.00%
Unrecognized tax benefits	$ 4.6		$ 4.6		$ 4.6
Accrued interest payable for taxes	0.8		0.8		0.7
Liability for income tax penalties	$ 0		$ 0		$ 0

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Liability for income tax penalties

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

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

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