Real Estate Transactions - Additional Information (Detail) $ in Thousands				3 Months Ended			6 Months Ended			12 Months Ended
	Apr. 01, 2025 USD ($) Bed	Mar. 07, 2025 USD ($) Bed	Jun. 10, 2024 Bed	Mar. 31, 2025 USD ($) Bed Facility	Sep. 30, 2024 USD ($)	Mar. 31, 2024 USD ($)	Sep. 30, 2025 USD ($)	Sep. 06, 2025 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)	Mar. 05, 2025 Bed
Facility Activations Developments And Closures [Line Items]
Operating expenses				$ 374,737		$ 378,103
Asset impairment					$ 3,100
Company Owned Bed | Bed			2,400								2,400
RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability				$ 116,900
ICE
Facility Activations Developments And Closures [Line Items]
Agreement notice period for termination			60 days
Lease Liabilities and Adjustments									$ 57,000
Idled Correctional Facilities
Facility Activations Developments And Closures [Line Items]
Number of facility | Facility				9
Idle Facilities
Facility Activations Developments And Closures [Line Items]
Operating expenses				$ 5,200		3,400
Two Community Corrections Facilities And Two Vacant Parcel Of Land [Member]
Facility Activations Developments And Closures [Line Items]
Net proceeds from sale of properties										$ 13,300
Gain on sale of properties										$ 3,300
Community
Facility Activations Developments And Closures [Line Items]
Operating expenses				$ 23,613		24,144
Community | Idle Facilities
Facility Activations Developments And Closures [Line Items]
Number of beds at the facility | Bed				60
Net carrying value				$ 1,100
Safety
Facility Activations Developments And Closures [Line Items]
Number of beds at the facility | Bed				65,000
Operating expenses				$ 347,983		$ 350,098
Safety | Idled Non-Core Facilities
Facility Activations Developments And Closures [Line Items]
Number of facility | Facility				1
Number of beds at the facility | Bed				240
Net carrying value				$ 2,700
Properties
Facility Activations Developments And Closures [Line Items]
Number of beds at the facility | Bed				10,000
Letter Agreement | Midwest Regional Reception Center | U.S. Immigration and Customs Enforcement
Facility Activations Developments And Closures [Line Items]
Number of beds at the facility | Bed		1,033
Initial award		$ 5,000
Letter Agreement | Midwest Regional Reception Center | U.S. Immigration and Customs Enforcement | Maximum
Facility Activations Developments And Closures [Line Items]
Maximum funding								$ 22,600
Letter Agreement | California City Immigration Processing Center | U.S. Immigration and Customs Enforcement
Facility Activations Developments And Closures [Line Items]
Initial award	$ 10,000
Letter Agreement | California City Immigration Processing Center | U.S. Immigration and Customs Enforcement | Maximum
Facility Activations Developments And Closures [Line Items]
Maximum funding							$ 31,200
Letter Agreement | California City Immigration Processing Center | U.S. Immigration and Customs Enforcement | Subsequent Event
Facility Activations Developments And Closures [Line Items]
Number of beds at the facility | Bed	2,560