Real Estate and Related Assets - Additional Information (Detail)	1 Months Ended	12 Months Ended
	Jun. 30, 2013 USD ($)	Dec. 31, 2020 USD ($) Property Facility	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Property, Plant and Equipment [Line Items]
Number of real estate properties owned | Property		69
Number of properties for lease to third parties and used by government agencies | Property		15
Number of facilities owned by government partners, managed | Facility		5
Interest capitalization cost on construction in progress		$ 500,000	$ 6,000,000.0	$ 1,000,000.0
Depreciation expense		$ 141,700,000	137,700,000	$ 152,000,000.0
Number of facilities subject to options | Facility		10
Number of facilities accounting for as service concession arrangements | Facility		4
Other real estate assets		$ 228,243,000	238,637,000
Purchase price paid for real property in addition to bonds value	$ 100
Contract Cost
Property, Plant and Equipment [Line Items]
Other real estate assets		143,600,000	147,800,000
Service Contract
Property, Plant and Equipment [Line Items]
Other real estate assets		$ 84,600,000	$ 90,800,000
Development Authority of Telfair County
Property, Plant and Equipment [Line Items]
Percentage of property tax abatement	90.00%
Percentage of property tax abatement, decrease in percentage	(10.00%)
Principal amount of bond issued	$ 15,000,000.0
Number of years of tax abatement	9 years