Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Operating Loss Carryforwards [Line Items]
Effective income tax rate reconciliation, percent			36.80%
Valuation allowance result in benefit of provision of income tax		$ (21.7)
Income tax expense (benefit)	$ 2.5	$ (17.4)	$ 7.1	$ (17.4)
Deferred tax assets not to be utilized in future period	$ 7.2		$ 7.2
Prior to September 30, 2015 [Member]
Operating Loss Carryforwards [Line Items]
Income tax expense (benefit)				$ 0.0
Percentage of valuation allowance, deferred tax assets		100.00%		100.00%