Change In Acquisition-Related Contingent Consideration Liability (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Business Acquisition, Contingent Consideration [Line Items]
Beginning balance	$ 8,237		$ 23,882		$ 14,990		$ 19,864
Acquisition date fair value measurement	1,150				1,150		3,000
Change in amount of contingent consideration	(403)		(944)		2,581		(2,538)
Payments					(1,287)		(577)
Elimination of contingency					(2,534)
Ending balance	9,850		24,731		9,850		24,731
Fair Value Adjustment
Business Acquisition, Contingent Consideration [Line Items]
Change in amount of contingent consideration	404	[1]	944	[1]	(2,581)	[1]	2,538	[1]
Foreign Currency Translation
Business Acquisition, Contingent Consideration [Line Items]
Change in amount of contingent consideration	$ 59		$ (95)		$ 112		$ (94)

[1] Adjustments to fair value related to accretion and remeasurement of contingent consideration are recorded in "Acquisition-related contingent consideration" on the Condensed Consolidated Statements of Comprehensive Income.