Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Net deferred income tax assets				$ 47.5
Effective rate tax adjustment related to federal tax, amount		$ 2.1
Decrease in effective tax rate		8.80%
Decrease in effective tax rate due to valuation allowance, percentage	42.40%		41.80%
Decrease in unrecognized tax positions		$ 1.9
Interest and penalties		$ 2.0