Derivative Instruments - Additional Information (Detail) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended			9 Months Ended					9 Months Ended
	Sep. 30, 2013 USD ($)	Sep. 30, 2012 USD ($)	Sep. 30, 2013 USD ($)	Sep. 30, 2012 USD ($)	Jan. 31, 2013	Sep. 30, 2013 Reclassification out of Accumulated Other Comprehensive Income USD ($)	Sep. 30, 2013 Interest Rate Swap USD ($)	Dec. 31, 2012 Interest Rate Swap USD ($)	Nov. 05, 2013 Interest Rate Swap Subsequent Event USD ($)	Jan. 31, 2013 Cross Currency Interest Rate Swap EUR (€)	Sep. 30, 2013 Minimum	Sep. 30, 2013 Maximum
Derivative Instrument [Line Items]
Foreign exchange contracts period											12 months	15 months
Derivative notional amount							$ 150	$ 200	$ 50	€ 60
Termination of the swaps					2014-06
Derivative instrument gains	$ (3.0)	$ (1.2)	$ 5.1	$ (3.3)		$ 3.0