Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Feb. 01, 2032	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Document Period End Date	Sep. 30, 2017
Derivative assets	$ 19.3		$ 110.2
Derivative liabilities	594.9		97.6
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market fund	3.2		4.3
Derivative assets	19.3		110.2
Derivative liabilities	594.9		97.6
Business Combination, Contingent Consideration, Liability, Noncurrent	84.0
Reported Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	19.3		110.2
Derivative liabilities	594.9		97.6
Level 1 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market fund	3.2		4.3
Derivative assets	0.0		0.0
Derivative liabilities	0.0		0.0
Business Combination, Contingent Consideration, Liability, Noncurrent	0.0
Level 2 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market fund	0.0		0.0
Derivative assets	19.3		110.2
Derivative liabilities	594.9		97.6
Business Combination, Contingent Consideration, Liability, Noncurrent	0.0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market fund	0.0		0.0
Derivative assets	0.0		0.0
Derivative liabilities	0.0		$ 0.0
Business Combination, Contingent Consideration, Liability, Noncurrent	$ 84.0
Scenario, Forecast [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability, Noncurrent		$ 84.0