Acquisitions - Priory Acquisition - Additional Information (Detail) - Priory [Member] $ in Billions	Jul. 28, 2016 Bed Facility	Feb. 16, 2016 USD ($) Bed Facility shares
Business Acquisition [Line Items]
Total consideration related to acquisition | $		$ 2.2
Business acquisition cash paid | $		$ 1.9
Shares issued for acquisition | shares		4,033,561
Number of facilities acquired | Facility		324
Number of beds | Bed		7,100
Subsequent Event [Member]
Business Acquisition [Line Items]
Number of facilities to be sold | Facility	19
Number of beds to be sold | Bed	750