Subsequent Events (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended	0 Months Ended
	Dec. 31, 2014	Feb. 06, 2015	Jan. 26, 2015	Jan. 28, 2015 bed
Subsequent Event [Line Items]
Vesting period	4 years
Restricted Stock Award
Subsequent Event [Line Items]
Granted shares	306,000
Subsequent Event
Subsequent Event [Line Items]
Options, grants in period		255,000
Dividends declared		$ 0.62
Subsequent Event | Restricted Stock Award
Subsequent Event [Line Items]
Granted shares		395,000
Subsequent Event | Performance-based Restricted Stock
Subsequent Event [Line Items]
Granted shares		124,000
Vesting period		3 years
Subsequent Event | LCS Facilities
Subsequent Event [Line Items]
Number of correctional and detention facilities acquired			8
Number of beds in acquired facilities			6,500
Payments to acquire LCS facilities			$ 310
Earnout period to exceed certain performance targets after the closing			18 months
Acquisition, consideration transferred			350.0
LCS Corrections Services, Inc. | Subsequent Event | LCS Facilities
Subsequent Event [Line Items]
Repayments of debt			298
Facility Management Contracts | Mesa Verde Detention Facility
Subsequent Event [Line Items]
Renovation costs of detention facility	10
Facility Management Contracts | Mesa Verde Detention Facility | Subsequent Event
Subsequent Event [Line Items]
Facility, number of beds				400