Dispositions and Acquisitions - Additional Information (Detail) - Entity [Domain]	6 Months Ended
Jun. 30, 2015 USD ($) Bed	Jun. 30, 2014 USD ($) Bed
Acquisitions And Divestitures [Line Items]
Cash paid/reserved related to acquisition of property and businesses	$ 34,500,000	$ 71,000,000
Number of beds \| Bed	24	66
Proceeds from Divestiture of Businesses	$ 0
Aggregate cash proceeds from divestiture of businesses		$ 11,000,000
Pre-tax gain (loss) proceeds from divestiture of businesses		$ 10,000,000
Cygnet Hospital-Taunton
Acquisitions And Divestitures [Line Items]
Number of beds \| Bed	46
Psychiatric Institute
Acquisitions And Divestitures [Line Items]
Number of beds \| Bed		124
Palo Verde Behavioral Health
Acquisitions And Divestitures [Line Items]
Number of beds \| Bed		48

Acquisitions And Divestitures [Line Items]

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- Definition

Gain Loss On Sale Of Business Before Tax

+ References

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- Definition

Number Of Beds Available In Acquired Hospital In Business Acquisition

+ References

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- Definition

The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3213-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

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- Definition

The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 12

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3179-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

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This element represents the cash inflow during the period from the sale of a component of the entity.

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