Changes to Contingent Consideration (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Business Acquisition, Contingent Consideration [Line Items]
Contingent consideration, beginning balance				$ 9,921					$ 9,921
Increases due to acquisitions									15,070
Decreases due to payments									(8,207)
Changes due to currency fluctuations									975
Changes in fair value reflected in income statement (SG&A)	161	(11)	(602)	1,204	(5,081)	0	0	(2,140)	752	(7,221)	0
Contingent consideration, ending balance	$ 18,511				$ 9,921				$ 18,511	$ 9,921