Commitments and Contingencies - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($) Bed LegalMatter	Aug. 27, 2015 Bed	Dec. 31, 1997 USD ($) Bed
Loss Contingencies [Line Items]
Number of pending legal proceedings that would have an effect on consolidated financial position, results of operations, or cash flows | LegalMatter	0
Number of beds at the facility | Bed	83,000	600
Hardeman County Correctional Facilities Corporation
Loss Contingencies [Line Items]
Issuance of revenue bonds			$ 72.7
Number of beds at the facility | Bed			2,016
Outstanding principal balance of revenue bonds	$ 12.8
Outstanding principal balance of the bonds exceeded the purchase price option	$ 4.9