Supplemental Cash Flow Information - Schedule Of Noncash Investing and Financing Activities (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Supplemental Cash Flow Elements [Abstract]
Accrued liabilities for purchases of property, plant and equipment	$ 21.4	$ 20.6
Accrued proceeds from company-owned life insurance benefits	0.8
Acquisition of assets through swap		1.1
Receivable issued in connection with sale of property, plant and equipment		1.3
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 12.7	16.9
Right-of-use assets obtained in exchange for new finance lease liabilities		$ 0.2