Derivative Financial Instruments - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative assets	$ 94.3		$ 137.3
Designated under hedge accounting
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative assets	$ 93.8		136.1
Cash Flow Hedging
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Maximum length of future cash flow hedges	5 years 2 months 12 days
Recognized gain (loss) on the ineffective portion	$ 0.0	$ 0.0
Accumulated net loss on derivative contracts included in accumulated other comprehensive loss expected to be recognized in the Consolidated Statements of Comprehensive Income in the following 12 months, net of tax	6.2
Gains or losses reclassified out of AOCI into net income based on the probability that the original forecasted transaction would not occur	0.6	0.0
Interest-Rate Contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional amount of outstanding contracts	3,481.6
Notional maturities for interest-rate contracts 2016	950.6
Notional maturities for interest-rate contracts 2017	762.3
Notional maturities for interest-rate contracts 2018	1,071.6
Notional maturities for interest-rate contracts 2019	362.9
Notional maturities for interest-rate contracts 2020	143.5
Notional maturities for interest-rate contracts thereafter	190.7
(Income) Expense recognized in earnings	0.0	0.0
Interest-Rate Contracts | Financial Services | Designated under hedge accounting | Other Assets
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative assets	90.3		$ 132.2
Foreign-exchange contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative notional amount outstanding	$ 318.2
Foreign-exchange contracts maturity period	Within one year
(Income) Expense recognized in earnings	$ 1.2	$ (14.3)