Dispositions and Acquisitions - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended			1 Months Ended		3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Palo Verde Behavioral Health Bed	Apr. 30, 2014 Arbor Group, L.L.C Subsequent Event Contract Bed	Apr. 30, 2014 Psychiatric Institute Subsequent Event Bed	Mar. 31, 2013 Previously Closed Facilities Facility
Significant Acquisitions and Disposals [Line Items]
Number of management contracts				3
Number of beds			48	66	124
Payment to acquired real properties			$ 3
Aggregate cash proceeds from divestiture of businesses	11	7
Pre-tax gain proceeds from divestiture of businesses	$ 10
Number of facilities						2