Basis of Presentation - Additional Information (Details) $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended
	Jan. 26, 2021 bed	Sep. 30, 2021 USD ($) bed facility person detainee	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) bed facility person detainee	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of beds		86,000		86,000
Correctional, detention and residential treatment facilities including projects under development | facility		107		107
Provision of monitoring services tracking offenders, number of individuals (more than) | person		200,000		200,000
Provision of monitoring services tracking offenders using technology products (in detainees) | detainee		100,000		100,000
Revenues | $		$ 557,277	$ 579,136	$ 1,699,073	$ 1,771,982
Ravenhall | Bureau Of Prisons B O P
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of beds in detention facility	1,940
Expiration date	May 31, 2021
Spring Correctional Facility | Bureau Of Prisons B O P
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of beds in detention facility	1,732
Expiration date	Nov. 30, 2021
Flightline Correctional Facility | Bureau Of Prisons B O P
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of beds in detention facility	1,800
Expiration date	Nov. 30, 2021
North Lake Correctional Facility | Bureau Of Prisons B O P
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of beds in detention facility	1,800
Expiration date	Sep. 30, 2022
Reeves County Detention Center I & II | Bureau Of Prisons B O P
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of beds in detention facility	1,800
Expiration date	Sep. 30, 2022
Reeves County Detention Center III | Bureau Of Prisons B O P
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of beds in detention facility	1,376
Expiration date	Jun. 30, 2022
Great Plains, Big Spring, Flightline, Northlake Correctional Facilities, Reeves County Detention Center I & II and Reeves County Detention Center III | Bureau Of Prisons B O P
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Revenues | $						$ 145,000