Cost-Reduction Actions - Individual Components of Work Force Reduction and Idle Lease Cost (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2018
Total
Restructuring Reserve [Roll Forward]
Balance at beginning of period	$ 117.8
Payments	(16.5)
Changes in estimates	(2.9)
Translation adjustments	2.9
Balance at end of period	101.3
2018 remaining nine months	69.4
Beyond 2018	69.4
Total | Forecast
Restructuring Reserve [Roll Forward]
2018 remaining nine months		$ 31.9
Beyond 2018		31.9
Work-Force Reductions | U.S.
Restructuring Reserve [Roll Forward]
Balance at beginning of period	3.9
Payments	(1.7)
Changes in estimates	(1.2)
Translation adjustments	0.0
Balance at end of period	1.0
2018 remaining nine months	1.0
Beyond 2018	1.0
Work-Force Reductions | U.S. | Forecast
Restructuring Reserve [Roll Forward]
2018 remaining nine months		0.0
Beyond 2018		0.0
Work-Force Reductions | International
Restructuring Reserve [Roll Forward]
Balance at beginning of period	109.6
Payments	(14.2)
Changes in estimates	(1.8)
Translation adjustments	2.8
Balance at end of period	96.4
2018 remaining nine months	67.1
Beyond 2018	67.1
Work-Force Reductions | International | Forecast
Restructuring Reserve [Roll Forward]
2018 remaining nine months		29.3
Beyond 2018		29.3
Idle Leased Facilities Costs
Restructuring Reserve [Roll Forward]
Balance at beginning of period	4.3
Payments	(0.6)
Changes in estimates	0.1
Translation adjustments	0.1
Balance at end of period	3.9
2018 remaining nine months	1.3
Beyond 2018	$ 1.3
Idle Leased Facilities Costs | Forecast
Restructuring Reserve [Roll Forward]
2018 remaining nine months		2.6
Beyond 2018		$ 2.6