Cost-Reduction Actions - Individual Components of Work Force Reduction and Idle Lease Cost (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2019
Restructuring Reserve [Roll Forward]
Changes in estimates		$ (2.9)
Work-force Reductions
Restructuring Reserve [Roll Forward]
Balance at beginning of period	$ 86.2
Payments	(13.9)
Changes in estimates	(1.0)
Translation adjustments	(0.2)
Balance at end of period	71.1
2019 remaining nine months	59.8
Beyond 2019	59.8
Work-force Reductions | Forecast
Restructuring Reserve [Roll Forward]
2019 remaining nine months			$ 11.3
Beyond 2019			11.3
Work-force Reductions | U.S.
Restructuring Reserve [Roll Forward]
Balance at beginning of period	6.1
Payments	(0.5)
Changes in estimates	(0.8)
Translation adjustments	0.0
Balance at end of period	4.8
2019 remaining nine months	4.8
Beyond 2019	4.8
Work-force Reductions | U.S. | Forecast
Restructuring Reserve [Roll Forward]
2019 remaining nine months			0.0
Beyond 2019			0.0
Work-force Reductions | International
Restructuring Reserve [Roll Forward]
Balance at beginning of period	80.1
Payments	(13.4)
Changes in estimates	(0.2)
Translation adjustments	(0.2)
Balance at end of period	66.3
2019 remaining nine months	55.0
Beyond 2019	$ 55.0
Work-force Reductions | International | Forecast
Restructuring Reserve [Roll Forward]
2019 remaining nine months			11.3
Beyond 2019			$ 11.3