Other expense, net (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Other Income and Expenses [Abstract]
Foreign currency transactions	$ (0.8)	$ (0.7)
Foreign currency denominated loans revaluation	0.2	5.2
Undesignated foreign currency derivative instruments	(2.0)	(9.9)
Undesignated swap contracts	(4.8)	0.2
Non-operating retirement benefits	2.2	0.6
Debt refinancing costs	(0.1)	0.0
Other	(0.6)	(1.5)
Total other expense	$ (5.9)	$ (6.1)