Changes in Carrying Amount of Goodwill (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Dec. 31, 2012
Goodwill [Line Items]
Gross Balance prior to the end of year			$ 548,573
Total impairment, beginning of period			(47,432)
Beginning Balance	501,141
Goodwill from acquisitions	104,905	[1]
Foreign currency translation adjustments	(2,377)
Ending Balance	603,669
Americas
Goodwill [Line Items]
Gross Balance prior to the end of year			316,222
Total impairment, beginning of period			(47,432)
Beginning Balance	268,790
Goodwill from acquisitions	104,905	[1]
Foreign currency translation adjustments	(59)
Ending Balance	373,636
EMEA
Goodwill [Line Items]
Gross Balance prior to the end of year			158,653
Total impairment, beginning of period
Beginning Balance	158,653
Goodwill from acquisitions		[1]
Foreign currency translation adjustments	(1,777)
Ending Balance	156,876
Asia /Pacific
Goodwill [Line Items]
Gross Balance prior to the end of year			73,698
Total impairment, beginning of period
Beginning Balance	73,698
Goodwill from acquisitions		[1]
Foreign currency translation adjustments	(541)
Ending Balance	$ 73,157

[1] Addition relates to the goodwill acquired in the acquisition of ORCC and PTESA as discussed in Note 2. The purchase price allocations for ORCC and PTESA are preliminary as of March 31, 2013 and accordingly are subject to future changes during the maximum one-year allocation period.