Commitments and Contingencies (Contract Awards) (Details) $ in Millions					1 Months Ended
	Jan. 01, 2019 bed renewal	Dec. 03, 2018 bed	Jun. 26, 2018 inmate	Mar. 29, 2018	Apr. 30, 2018 bed	Dec. 31, 2018 USD ($)
George W. Hill Correctional Facility | Delaware County Board Of Prison Inspectors
Loss Contingencies [Line Items]
Number of beds in detention facility	1,931
Number management contract renewal options | renewal	2
Renewal term	2 years
Allen Correctional Facility
Loss Contingencies [Line Items]
Number of beds in detention facility terminated					1,576
Junee Correctional Centre | State Of New South Wales, Corrective Services
Loss Contingencies [Line Items]
Number of beds in detention facility		1,279
Life term of contract		5 years
Number of beds in detention facility added		489
Eagle Pass Detention Facility | Idaho Department Of Corrections
Loss Contingencies [Line Items]
Number of inmates, capacity | inmate			670
Facility operation contract term			2 years
Prisoner Escort Services | Scottish Prison Service
Loss Contingencies [Line Items]
Renewal term				4 years
Facility operation contract term				8 years
Parklea Correctional Centre
Loss Contingencies [Line Items]
Accrued employee benefits | $						$ 3