Acquisitions (Details 2) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013
Business Acquisition [Line Items]
Liability as of December 31, 2012	$ 3,084
2013 Additions (Payments)	2,509
Change in Fair Value of Contingent Consideration	(427)
Foreign Currency Translation	(48)
Liability as of September 30, 2013	5,118
Milsom [Member]
Business Acquisition [Line Items]
Liability as of December 31, 2012	302
2013 Additions (Payments)	(299)
Change in Fair Value of Contingent Consideration	0
Foreign Currency Translation	(3)
Liability as of September 30, 2013	0
Marton House [Member]
Business Acquisition [Line Items]
Liability as of December 31, 2012	774
2013 Additions (Payments)	(759)
Change in Fair Value of Contingent Consideration	32
Foreign Currency Translation	(47)
Liability as of September 30, 2013	0
Bath Consulting [Member]
Business Acquisition [Line Items]
Liability as of December 31, 2012	1,464
2013 Additions (Payments)	(676)
Change in Fair Value of Contingent Consideration	232
Foreign Currency Translation	(40)
Liability as of September 30, 2013	980
Asentus [Member]
Business Acquisition [Line Items]
Liability as of December 31, 2012	544
2013 Additions (Payments)	0
Change in Fair Value of Contingent Consideration	(533)
Foreign Currency Translation	(11)
Liability as of September 30, 2013	0
Prospero [Member]
Business Acquisition [Line Items]
Liability as of December 31, 2012	0
2013 Additions (Payments)	3,670
Change in Fair Value of Contingent Consideration	(436)
Foreign Currency Translation	11
Liability as of September 30, 2013	3,245
Lorien [Member]
Business Acquisition [Line Items]
Liability as of December 31, 2012	0
2013 Additions (Payments)	573
Change in Fair Value of Contingent Consideration	278
Foreign Currency Translation	42
Liability as of September 30, 2013	$ 893