Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Valuation allowance for net deferred tax assets	$ 7.0		$ 7.0		$ 28.7
Valuation allowance result in benefit of provision of income tax	(21.7)		(21.7)
Deferred tax assets not to be utilized in future period	7.0		7.0
Income tax expense or benefit	(17.4)		(17.4)	$ 0.0
Income from continuing operations before income taxes	5.8	$ 3.6	11.3	6.2
Income from continuing operations	23.2	3.6	28.7	6.2
Income tax expense (benefit) from discontinued operations			(1.8)
Income (loss) from discontinued operation before tax			(4.9)
Gross deferred tax assets	35.0		35.0
Net deferred tax assets	28.0		28.0
Deferred tax liabilities	8.7		8.7
Short term deferred tax liabilities	3.5		3.5
Current net deferred tax liabilities	5.2	7.5	5.2	7.5	8.0
Long term deferred tax assets	$ 24.5	$ 7.5	$ 24.5	$ 7.5	$ 8.0