Stockholders' Equity - Additional Information (Detail) - USD ($)			3 Months Ended			9 Months Ended		12 Months Ended
	Aug. 25, 2021	Feb. 20, 2020	Sep. 30, 2021	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Dividend declaration Date		Feb. 20, 2020
Dividends declared on common stock, per share		$ 0.44			$ 0.44
Dividend payable date		Apr. 15, 2020
Dividend payable record date		Apr. 01, 2020
Common stock, par value			$ 0.01			$ 0.01		$ 0.01
Common stock, shares issued			120,285,000			120,285,000		119,638,000
Termination of ATM Agreement
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Common stock, par value	$ 0.01
Common stock, shares issued	0
Maximum | Common Stock | Termination of ATM Agreement
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Common stock, aggregate gross sales price	$ 200,000,000.0
Restricted stock based awards
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Fair value of restricted common stock units issued by CoreCivic to certain of its employees and non-employee directors						$ 21,800,000		$ 20,900,000
Vesting description						The RSUs awarded to officers and executive officers in 2019, 2020 and 2021 consist of a combination of awards with performance-based conditions and time-based conditions.  Unless earlier vested under the terms of the RSU agreements, the RSUs with time-based vesting conditions vest evenly generally on the first, second, and third anniversary of the award. The RSUs with performance-based vesting conditions are divided into one-third increments, each of which is subject to vesting based upon satisfaction of certain annual performance criteria established at the beginning of the fiscal years ending December 31, 2019, 2020, and 2021 for the 2019 awards, December 31, 2020, 2021, and 2022 for the 2020 awards, and December 31, 2021, 2022, and 2023 for the 2021 awards, and which can be increased up to 150% or decreased to 0% based on performance relative to the annual performance criteria, and further increased or decreased using a modifier of 80% to 120% based on CoreCivic's total shareholder return relative to a peer group.  Because the performance criteria for the fiscal years ending December 31, 2022 and 2023 have not yet been established, the values of the third RSU increment of the 2020 awards and of the second and third increments of the 2021 awards for financial reporting purposes will not be determined until such criteria are established.
Increase in vesting percentage based on performance relative to annual performance criteria						150.00%
Decrease in vesting percentage based on performance relative to annual performance criteria						0.00%
Allocated share-based compensation expense			$ 5,100,000	$ 4,100,000		$ 13,600,000	$ 13,000,000.0
Restricted common stock units remained outstanding and subject to vesting			3,500,000			3,500,000
Restricted stock based awards | Minimum
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Increase decrease in vesting percentage based on shareholder return relative to peer group						80.00%
Restricted stock based awards | Maximum
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Increase decrease in vesting percentage based on shareholder return relative to peer group						120.00%
Restricted stock based awards | General and Administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense			$ 4,700,000	3,700,000		$ 12,400,000	11,700,000
Restricted stock based awards | Operating
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense			$ 400,000	$ 400,000		$ 1,200,000	$ 1,300,000
Restricted stock based awards | Employees And Non Employee Directors
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Restricted common stock units issued by CoreCivic						2,700,000		1,200,000
Restricted stock based awards | Employees And Non Employee Directors | General and Administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Restricted common stock units issued by CoreCivic						2,500,000		1,100,000
Restricted stock based awards | Employee | Operating
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Restricted common stock units issued by CoreCivic						200,000		100,000
Restricted stock based awards | Officers And Executive Officers
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Vesting period						3 years
Percent of awards eligible to vest						33.33%
Restricted stock based awards | Non Employee Directors
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Vesting period						1 year
Restricted stock based awards | Other Employees
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Vesting period, continuous service requirement						3 years