Plant Closures and Divestitures - Summary of Restructuring Activities and Related Reserves (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Reserve, Beginning Balance	$ 4.0	$ 8.1
Accrual		6.4
Cost charged against assets		(3.0)
Reversal of accrued charges	(0.2)	(0.4)
Cash paid		(7.0)
Currency translation		(0.1)
Reserve, Ending Balance	3.8	4.0
Severance and Employee Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Reserve, Beginning Balance	0.9	1.7
Accrual		0.0
Cost charged against assets		(0.0)
Reversal of accrued charges	(0.2)	(0.3)
Cash paid		(0.5)
Currency translation		0.0
Reserve, Ending Balance	0.7	0.9
Asset Retirement [Member]
Restructuring Cost and Reserve [Line Items]
Reserve, Beginning Balance	0.7	3.6
Accrual		3.4
Cost charged against assets		(0.0)
Reversal of accrued charges	(0.0)	(0.1)
Cash paid		(6.2)
Currency translation		0.0
Reserve, Ending Balance	0.7	0.7
Other [Member]
Restructuring Cost and Reserve [Line Items]
Reserve, Beginning Balance	2.4	2.8
Accrual		3.0
Cost charged against assets		(3.0)
Reversal of accrued charges	(0.0)	(0.0)
Cash paid		(0.3)
Currency translation		(0.1)
Reserve, Ending Balance	$ 2.4	$ 2.4