Other Assets, net - Components of Other Assets, Net (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Other Assets [Abstract]
Amortization expense	$ 4.3	$ 10.1	$ 9.3	$ 22.0