Summary of Net Gain (Loss) on Foreign Exchange Forwards Not Designated as Hedging Instruments and on Interest Rate Swaps Designated as Fair Value Hedges (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Derivatives Designated as Accounting Hedges [Member] | Interest Rate Swap [Member] | Interest Income (Expense), Net [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in income	$ 1.8	$ 3.1	$ 4.2	$ 6.1
Derivatives Not Designated as Accounting Hedges [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in income	48.3	(5.7)	46.0	(5.2)
Derivatives Not Designated as Accounting Hedges [Member] | Foreign Exchange Forward [Member] | Other Nonoperating Income (Expense) [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in income	7.1	$ (5.7)	4.8	$ (5.2)
Bureau van Dijk (BvD) [Member] | Derivatives Not Designated as Accounting Hedges [Member] | Foreign Exchange Forward [Member] | Purchase price hedge [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in income	$ 41.2		$ 41.2