Derivatives - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended	3 Months Ended						3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2014 Fair Value Hedging	Mar. 31, 2013 Fair Value Hedging	Mar. 20, 2014 Senior Notes Eight Point Two Five Percent Due March Fifteen Two Thousand Nineteen	Mar. 31, 2014 Senior Notes Eight Point Two Five Percent Due March Fifteen Two Thousand Nineteen	Mar. 31, 2012 Senior Notes Eight Point Two Five Percent Due March Fifteen Two Thousand Nineteen	Mar. 13, 2012 Senior Notes Eight Point Two Five Percent Due March Fifteen Two Thousand Nineteen	Mar. 31, 2012 Senior Notes Four Point Nine Five Percent Due April One Two Thousand Fourteen	Mar. 31, 2014 Senior Notes Four Point Nine Five Percent Due April One Two Thousand Fourteen	Apr. 09, 2010 Senior Notes Four Point Nine Five Percent Due April One Two Thousand Fourteen	Mar. 31, 2014 Not Designated as Hedging Instrument Foreign Exchange Contract	Dec. 31, 2013 Not Designated as Hedging Instrument Foreign Exchange Contract	Mar. 13, 2012 Designated Fair Value Hedges Interest Rate Swap	Apr. 09, 2010 Designated Fair Value Hedges Interest Rate Swap	Mar. 31, 2014 Designated Fair Value Hedges Interest Rate Swap Senior Notes Eight Point Two Five Percent Due March Fifteen Two Thousand Nineteen	Mar. 31, 2014 Designated Fair Value Hedges Interest Rate Swap Senior Notes Four Point Nine Five Percent Due April One Two Thousand Fourteen
Derivative [Line Items]
Aggregate notional value													$ 394.2	$ 372.1	$ 400.0	$ 600.0	$ 190.0	$ 258.0
Derivative, inception date								Mar. 13, 2012		Apr. 09, 2010
Debt instrument, face amount							239.0		450.0		258.2
Interest rate						8.25%	8.25%		8.25%		4.95%	4.95%
Maturity date						Mar. 15, 2019	Mar. 15, 2019	Mar. 15, 2019		Apr. 01, 2014
Repayment of Debt	552.5	386.5				211.0	211.0			341.8
Terminated portion of interest rate swap agreement, notional amount							210.0			342.0
Payment for termination of interest rate swaps							4.2
Proceeds from termination of interest rate swaps			11.0
Reduction to interest expense	$ 71.0	$ 62.8		$ 2.3	$ 2.3