Goodwill and Other Intangible Assets - Goodwill (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning of period	$ 778,951
Acquisition Adjustments	(2,549)
Foreign Currency Translation	(23)
Goodwill, end of period	776,379
U.S. Corrections & Detention
Goodwill [Roll Forward]
Goodwill, beginning of period	317,005
Acquisition Adjustments	(639)
Foreign Currency Translation	0
Goodwill, end of period	316,366
GEO Care
Goodwill [Roll Forward]
Goodwill, beginning of period	461,499
Acquisition Adjustments	(1,910)
Foreign Currency Translation	0
Goodwill, end of period	459,589
International Services
Goodwill [Roll Forward]
Goodwill, beginning of period	447
Acquisition Adjustments	0
Foreign Currency Translation	(23)
Goodwill, end of period	$ 424