Dispositions and Acquisitions - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Significant Acquisitions and Disposals [Line Items]
Cash paid/reserved related to acquisition of property and businesses	$ 71,000,000	$ 1,320,000
Aggregate cash proceeds from divestiture of businesses	11,000,000	34,000,000
Pre-tax gain proceeds from divestiture of businesses	$ 10,000,000
Arbor Group, L.L.C
Significant Acquisitions and Disposals [Line Items]
Number of management contracts	3
Number of beds	66
Psychiatric Institute
Significant Acquisitions and Disposals [Line Items]
Number of beds	124
Palo Verde Behavioral Health
Significant Acquisitions and Disposals [Line Items]
Number of beds	48
Previously Closed Facilities
Significant Acquisitions and Disposals [Line Items]
Number of facilities		3
Peak Behavioral Health Services
Significant Acquisitions and Disposals [Line Items]
Number of acute care hospital beds included in sale		104