Other (Expense) Income, net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Other Income and Expenses [Abstract]
Interest and dividend income	$ 3.2	$ 2.0	$ 5.4	$ 3.6
Net foreign exchange transaction (losses) gains	(3.5)	5.2	(7.5)	4.8
Bank fee expense	(1.4)	(1.4)	(3.2)	(2.7)
Net (loss) gain on disposals of business and property and equipment	(0.1)	(0.5)	2.2	(3.1)
Other, net	(2.1)	(0.8)	(3.1)	(1.6)
Other (expense) income, net	$ (3.9)	$ 4.5	$ (6.2)	$ 1.0