Schedule - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Doubtful Accounts [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 51.6	$ 34.1	$ 22.3
Additions Charged (Credited) to Expense	13.6	22.3	13.5
Deductions to Reserve	(5.1)	(4.5)	(0.4)
Effects of Foreign Currency	0.1	(0.3)	(1.3)
Balance at End of Period	60.2	51.6	34.1
Deferred Tax Asset Valuation Allowances [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	88.3	72.7	122.8
Additions Charged (Credited) to Expense	41.3	24.8	(53.7)
Deductions to Reserve	(10.3)	(12.4)	(5.6)
Effects of Foreign Currency	2.8	(1.1)	(1.6)
Acquired Allowances	18.5	4.3	10.8
Balance at End of Period	$ 140.6	$ 88.3	$ 72.7