Components of lease expense (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020		Mar. 31, 2019
Short term lease expense	$ 0.4		$ 0.4
Variable lease expenses	0.4		0.8
Cost of products sold [Member]
Operating lease expense	0.7	[1]	0.7	[2]
Selling, general and administrative expenses [Member]
Operating lease expense	$ 4.0	[1]	$ 4.9	[2]

[1] 2020 includes short-term and variable lease expenses of $0.4 million and $0.4 million, respectively.

[2] 2019 includes short-term and variable lease expenses of $0.4 million and $0.8 million, respectively.