Other Expense, net - Details of Other Expense, Net (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Other Income And Expenses [Abstract]
Interest and dividend income	$ 2.2	$ 1.6
Net foreign exchange transaction losses	(4.0)	(0.4)
Bank fee expense	(1.8)	(1.3)
Net gain/(loss) on disposals of business and property and equipment	2.3	(2.6)
Other, net	(1.0)	(0.8)
Other expense, net	$ (2.3)	$ (3.5)