Derivative Instruments and Hedging Activities - Schedule of Effects of Master Netting Agreements on Condensed Consolidated Balance Sheets (Detail) - Cash Flow Hedges [Member] - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Other Current Assets [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gross Amount	$ 7.3	$ 14.5
Offset	7.0	13.4
Net Amount in Balance Sheet	0.3	1.1
Other Assets [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gross Amount	4.0	4.8
Offset	3.7	4.3
Net Amount in Balance Sheet	0.3	0.5
Other Current Liabilities [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gross Amount	56.0	45.8
Offset	7.0	13.4
Net Amount in Balance Sheet	49.0	32.4
Other Long-term Liabilities [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gross Amount	27.8	22.8
Offset	3.7	4.3
Net Amount in Balance Sheet	$ 24.1	$ 18.5