Derivatives - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended	3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	Jun. 30, 2014 Fair Value Hedging	Jun. 30, 2013 Fair Value Hedging	Jun. 30, 2014 Fair Value Hedging	Jun. 30, 2013 Fair Value Hedging	Mar. 31, 2012 Senior Notes Eight Point Two Five Percent Due March Fifteen Two Thousand Nineteen	Jun. 30, 2014 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, 2014 Senior Notes Four Point Nine Five Percent Due April One Two Thousand Fourteen	Mar. 31, 2012 Senior Notes Four Point Nine Five Percent Due April One Two Thousand Fourteen	Jun. 30, 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	Jun. 30, 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	Jun. 30, 2014 Designated Fair Value Hedges Interest Rate Swap Senior Notes Eight Point Two Five Percent Due March Fifteen Two Thousand Nineteen
Derivative [Line Items]
Aggregate notional value																	$ 360.3	$ 372.1	$ 400.0	$ 600.0	$ 190.0
Derivative, inception date										Mar. 13, 2012				Apr. 09, 2010
Debt instrument, face amount											238.9	450.0
Interest rate											8.25%	8.25%			4.95%	4.95%
Maturity date										Mar. 15, 2019	Mar. 15, 2019			Apr. 01, 2014	Apr. 01, 2014
Repayment of Debt			811.0	386.8							211.1		258.2	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	$ 70.8	$ 65.5	$ 141.8	$ 128.3		$ 0.5	$ 2.2	$ 2.8	$ 4.5