Supplemental Cash Flow Information -Supplemental Disclosures of Cash Flow Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Supplemental Cash Flow Elements [Abstract]
Cash paid for interest, net of amount capitalized	$ 127.9	$ 137.2	$ 78.9
Cash paid for income taxes	101.7	$ 28.9	$ 155.8
Operating cash flows used for operating leases	76.1
Operating cash flows used for finance leases	0.5
Financing cash flows used for finance leases	$ 11.0