Fair Value Measurements - Additional Information (Detail) In Millions, unless otherwise specified	12 Months Ended								12 Months Ended
	Dec. 31, 2013 USD ($) Contract	Dec. 31, 2012 Contract	Dec. 31, 2011 Contract	May 24, 2010 USD ($)	May 07, 2008 USD ($)	May 07, 2008 EUR (€)	Dec. 31, 2013 Forward Contract To Sell [Member] GBP (£)	Dec. 31, 2013 Forward Contract To Purchase [Member] USD ($)	Dec. 31, 2013 Forward Contracts [Member]
Derivative [Line Items]
30-day forward contract outstanding				$ 50.0	$ 28.0	€ 18.3	£ 3.0	$ 5.0
Number of forward contracts outstanding	1	0	0
Forward contract terms	30-day forward contracts								30-day forward contract
Increase in the contingent acquisition consideration	$ 0.2