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, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Other Current Assets [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gross Amount	$ 134.7	$ 98.7
Offset	12.4	15.9
Net Amount in Balance Sheet	122.3	82.8
Other Assets [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gross Amount	66.0	53.1
Offset	8.6	10.4
Net Amount in Balance Sheet	57.4	42.7
Other Current Liabilities [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gross Amount	12.6	16.4
Offset	12.4	15.9
Net Amount in Balance Sheet	0.2	0.5
Other Long-term Liabilities [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gross Amount	8.6	11.6
Offset	8.6	10.4
Net Amount in Balance Sheet		$ 1.2