Change In Acquisition-Related Contingent Consideration Liability (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Business Acquisition, Contingent Consideration [Line Items]
Beginning balance	$ 16,296		$ 15,276		$ 16,426		$ 14,990
Acquisition	5,377	[1]			4,528	[1]
Change in amount of contingent consideration	7,452		3,541		6,721		2,984
Payments	(235)		(917)		(235)		(1,287)
Elimination of contingency			(2,534)	[2]			(2,534)	[2]
Ending balance	13,285		8,237		13,285		8,237
Fair Value Adjustment
Business Acquisition, Contingent Consideration [Line Items]
Change in amount of contingent consideration	(7,452)	[3]	(3,541)	[3]	(6,721)	[3]	(2,984)	[3]
Foreign Currency Translation
Business Acquisition, Contingent Consideration [Line Items]
Change in amount of contingent consideration	$ (701)		$ (47)		$ (713)		$ 52

[1] Includes adjustments during the purchase price allocation period.

[2] During the three months ended June 30, 2012, we fixed an acquisition-related contingent consideration liability in the amount of $2.5 million. The non-contingent consideration liability is no longer required to be remeasured to fair value and, accordingly, is not classified as a Level 3 measurement.

[3] Includes adjustments to fair value related to accretion and remeasurement of contingent consideration which are recorded in "Acquisition-related contingent consideration" on the Condensed Consolidated Statements of Comprehensive Income (Loss).