Basis of Presentation - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax provision	$ (21.3)	$ (15.8)	$ (73.8)	$ (91.0)
Accounting Standards Update 2016-16
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect on retained earnings, net of tax			5.2
Impact on other current assets			5.4
Deferred tax liability, intra-entity transfer, asset other than inventory	0.2		0.2
Accounting Standards Update 2016-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax provision	$ 12.8		50.3
Accounting Standards Update 2016-18
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in restricted cash			$ 73.1