Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Effective tax rate from continuing operations	106.10%	18.20%	5.90%	(21.20%)
Effective income tax rate reconciliation, at federal statutory income tax rate, percent			21.00%	21.00%
Change in tax rate, income tax expense (benefit)				$ 6.0