Other Assets, net - Components of Other Assets (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Intangible Assets Net Excluding Goodwill [Abstract]
Amortization expense	$ 3.2	$ 4.2	$ 10.3	$ 13.5