Other Assets, net - Components of Other Assets, Net (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Other Assets [Abstract]
Amortization expense	$ 4.2	$ 18.1	$ 13.5	$ 28.2