Real Estate Transactions - Additional Information (Detail) $ in Thousands, shares in Millions							1 Months Ended	3 Months Ended				9 Months Ended
	Jun. 29, 2021 USD ($) Property	Jun. 25, 2021 USD ($) ft²	May 28, 2021 USD ($) Property	May 24, 2021 USD ($) ft²	Dec. 23, 2020 USD ($) Property	Jan. 02, 2020 USD ($) Property shares	Feb. 28, 2021 Facility Agreement	Sep. 30, 2021 USD ($) Bed	Jun. 30, 2021 USD ($) Property	Mar. 31, 2021 USD ($)	Sep. 30, 2020 USD ($) Bed	Sep. 30, 2021 USD ($) Facility Bed	Sep. 30, 2020 USD ($) Bed	Apr. 30, 2021 Bed	Jun. 30, 2020 Bed	Dec. 31, 2019 Bed
Facility Activations Developments And Closures [Line Items]
Number of properties acquired | Property					28	28
Purchase price of real estate						$ 83,200
Cash payments to acquire properties						7,700
Debt assumed on acquisition of property						$ 52,200							$ 52,217
Conversion holding period of operating partnership units						2 years
Operating partnership units description												one-for-one basis
Purchase price, net tangible assets						$ 77,400
Purchase price, identifiable intangible assets						7,500
Purchase price, tenant improvements						$ 4,900
Number of properties sold | Property	1		2		42				3
Real estate investment property aggregate selling price	$ 253,000		$ 73,000		$ 106,500
Net proceeds after the repayment of debt	$ 76,400		$ 46,200		27,800
Net loss on sale properties, after recognizing tax protection payments					$ 17,900
Net gain (loss) on sale of properties									$ 38,900
Asset impairments								$ 5,177			$ 805	$ 9,351	13,058
Operating Expense								338,192			347,927	1,004,146	1,063,169
West Tennessee Detention Facility
Facility Activations Developments And Closures [Line Items]
Net carrying value								$ 20,700				$ 20,700
Number of beds at the facility | Bed								600				600
Safety
Facility Activations Developments And Closures [Line Items]
Number of beds at the facility | Bed								70,000				70,000
Community
Facility Activations Developments And Closures [Line Items]
Number of beds at the center | Bed								5,000				5,000
Idled Non-Core Facilities
Facility Activations Developments And Closures [Line Items]
Net gain (loss) on sale of properties				$ (200)
Area of properties sold | ft²		18,000		12,000
Net carrying value		$ 2,000		$ 800
Net proceeds from sale of properties		$ 1,800		$ 600
Asset impairments										$ 1,300
Idled Non-Core Facilities | Safety
Facility Activations Developments And Closures [Line Items]
Net carrying value								$ 2,900				$ 2,900
Number of facility | Facility												1
Number of beds at the facility | Bed								240				240
Idled Correctional Facilities
Facility Activations Developments And Closures [Line Items]
Number of facility | Facility												5
Idle Facilities
Facility Activations Developments And Closures [Line Items]
Number of beds at the facility | Bed														90	60
Operating Expense								$ 2,000			$ 2,000	$ 6,000	$ 5,700
Idle Facilities | Community
Facility Activations Developments And Closures [Line Items]
Net carrying value								$ 13,500				$ 13,500
Number of facility | Facility												4
Number of beds at the center | Bed								740				740
Tulsa Transitional Center | Covid-19
Facility Activations Developments And Closures [Line Items]
Number of beds at the center | Bed											390		390
Oklahoma City Transitional Center | Covid-19
Facility Activations Developments And Closures [Line Items]
Number of beds at the center | Bed															200
Turley Residential Center in Oklahoma
Facility Activations Developments And Closures [Line Items]
Number of beds at the center | Bed																289
GRES
Facility Activations Developments And Closures [Line Items]
Number of properties acquired | Property						24
Class A Common interest shares issued | shares						1.3
Percentage of voting control						100.00%
Increase to stockholders' equity upon termination of partnership												$ 17,400
Alabama Department of Corrections ("ADOC")
Facility Activations Developments And Closures [Line Items]
Asset impairments								$ 5,200
Number of lease agreements | Agreement							2
Lease term							30 years
Number of correctional facilities | Facility							2