Derivative Instruments - Financial Information Related to Hedging of Net Assets Included in Consolidated Statement of Earnings (Detail) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2013 Foreign Exchange Forward [Member] Pound/US Dollar [Member] GBP (£)	Dec. 31, 2012 Foreign Exchange Forward [Member] Pound/US Dollar [Member] GBP (£)	Dec. 31, 2013 Foreign Exchange Forward [Member] Euro/US Dollar [Member] EUR (€)	Dec. 31, 2012 Foreign Exchange Forward [Member] Euro/US Dollar [Member] EUR (€)
Derivative [Line Items]
Change in gains (losses) from foreign exchange derivatives	$ (1,998)	$ (1,347)	$ (825)
Gain (loss) on net foreign currency assets	1,474	406	(1,181)
Net foreign exchange loss	(524)	(941)	(2,006)
Notional balance of outstanding contracts versus the dollar				0	3,810	41,021	37,598
Net fair value of outstanding contracts	$ 33	$ 18