Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Allowance for estimated credit losses/ doubtful accounts
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period		$ 4.7	$ 3.3	$ 2.4
Charged to costs and expenses		1.2	1.4	0.9
Balance at end of period		5.9	4.7	3.3
Allowance for estimated credit losses on notes receivable/ uncollectible notes receivable
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period				0.2
Charged to costs and expenses		0.4
Deductions-describe	[1]			0.2
Balance at end of period		0.4
Inventory valuation allowance
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period		168.6	159.2	144.0
Charged to costs and expenses		51.3	38.8	36.9
Charged to other accounts-describe	[2]			5.1
Deductions-describe	[3]	39.6	29.4	26.8
Balance at end of period		$ 180.3	$ 168.6	$ 159.2

[1] Write-off of uncollectible accounts and change in estimates

[2] Application of reserve policy to acquired inventories

[3] Sale of reserved inventory and divestitures