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	Jun. 30, 2015	Dec. 31, 2014
Other Current Assets [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gross Amount	$ 110.7	$ 98.7
Offset	7.2	15.9
Net Amount in Balance Sheet	103.5	82.8
Other Assets [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gross Amount	37.4	53.1
Offset	5.3	10.4
Net Amount in Balance Sheet	32.1	42.7
Other Current Liabilities [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gross Amount	7.2	16.4
Offset	7.2	15.9
Net Amount in Balance Sheet		0.5
Other Long-term Liabilities [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gross Amount	5.3	11.6
Offset	$ 5.3	10.4
Net Amount in Balance Sheet		$ 1.2