Dispositions and Acquisitions and Purchase of Third-Party Ownership Interests - Additional Information (Detail) $ in Thousands	1 Months Ended	3 Months Ended	9 Months Ended
	May 31, 2016 USD ($) Hospital	Jun. 30, 2016 USD ($) Hospital	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($) Bed
Acquisitions And Divestitures [Line Items]
Acquisition of property and businesses			$ 19,610	$ 136,221
Pahrump, Nevada
Acquisitions And Divestitures [Line Items]
Number of beds | Bed				25
Las Vegas, Nevada | Acute Care Hospital Services
Acquisitions And Divestitures [Line Items]
Payments to purchase minority ownership interests	$ 445,000	$ 445,000
Number of hospital facilities | Hospital	6	6
Purchase price of minority ownership interests	$ 418,000	$ 418,000
Return of reserve capital to purchase of minority ownership interests	$ 27,000	$ 27,000
Las Vegas, Nevada | Acute Care Hospital Services | Minimum
Acquisitions And Divestitures [Line Items]
Ownership interests purchased	26.10%	26.10%
Las Vegas, Nevada | Acute Care Hospital Services | Maximum
Acquisitions And Divestitures [Line Items]
Ownership interests purchased	27.50%	27.50%