Intangible Assets (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($)
Goodwill [Roll Forward]
Beginning Balance	$ 127,772
Acquisitions	12,685
Foreign currency translation	3,917
Ending Balance	144,374
Learning Solutions
Goodwill [Roll Forward]
Beginning Balance	49,079
Acquisitions	6,384
Foreign currency translation	3,041
Ending Balance	58,504
Professional and Technical Services
Goodwill [Roll Forward]
Beginning Balance	42,364
Acquisitions	0
Foreign currency translation	616
Ending Balance	42,980
Sandy Training and Marketing
Goodwill [Roll Forward]
Beginning Balance	653
Acquisitions	0
Foreign currency translation	0
Ending Balance	653
Performance Readiness Group
Goodwill [Roll Forward]
Beginning Balance	35,676
Acquisitions	6,301
Foreign currency translation	260
Ending Balance	$ 42,237