SEGMENT INFORMATION (Carrying Amount of Goodwill) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2015 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 239,256
Foreign currency translation adjustment	(71)
Goodwill, ending balance	239,185
Tech & Clearance [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	95,946
Foreign currency translation adjustment	112
Goodwill, ending balance	96,058
Finance [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	53,473
Foreign currency translation adjustment	540
Goodwill, ending balance	54,013
Energy [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	50,187
Foreign currency translation adjustment	0
Goodwill, ending balance	50,187
Healthcare Segment [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	6,269
Foreign currency translation adjustment	0
Goodwill, ending balance	6,269
Hospitality Segment [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	15,871
Foreign currency translation adjustment	(934)
Goodwill, ending balance	14,937
Corporate & Other Segment [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	17,510
Foreign currency translation adjustment	211
Goodwill, ending balance	$ 17,721