Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
Goodwill [Roll Forward]
Beginning Balance	$ 116,987
Acquisitions	12,338
Foreign currency translation	(1,811)
Ending Balance	127,514
Learning Solutions [Member]
Goodwill [Roll Forward]
Beginning Balance	60,187
Acquisitions	12,338
Foreign currency translation	(1,773)
Ending Balance	70,752
Professional and Technical Services [Member]
Goodwill [Roll Forward]
Beginning Balance	37,690
Acquisitions	0
Foreign currency translation	0
Ending Balance	37,690
Sandy [Member]
Goodwill [Roll Forward]
Beginning Balance	653
Acquisitions	0
Foreign currency translation	0
Ending Balance	653
Performance Readiness Group [Member]
Goodwill [Roll Forward]
Beginning Balance	9,795
Acquisitions	0
Foreign currency translation	0
Ending Balance	9,795
Energy Services [Member]
Goodwill [Roll Forward]
Beginning Balance	8,662
Acquisitions	0
Foreign currency translation	(38)
Ending Balance	$ 8,624