Commitments and Contingencies - Additional Information (Detail) £ in Millions	12 Months Ended							57 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 GBP (£)	Dec. 31, 2017 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($) Hospital	Dec. 31, 2018 USD ($)	Jan. 31, 2017 USD ($)	Jan. 31, 2017 GBP (£)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Commitments and Contingencies Disclosure [Line Items]
Self-insured for professional and general liability	$ 314,941,000		$ 298,222,000					$ 314,941,000			$ 274,815,000	$ 271,476,000
Self-insured for professional and general liability, current	42,000,000		54,000,000					42,000,000
Compensation liability claims	72,000,000		70,000,000					72,000,000
Compensation and related benefits	40,000,000		35,000,000					40,000,000
Combined estimated future purchase obligations	254,000,000							254,000,000
Defined benefit pension plan estimated payments through 2089	180,000,000							180,000,000
Other retirement plan liabilities	21,000,000							21,000,000
Department of Human Services
Commitments and Contingencies Disclosure [Line Items]
Repayment of legal settlement amount on demand				$ 4,000,000	$ 4,000,000	$ 4,000,000	$ 4,000,000
Amount claimed from over payments of legal settlements				7,000,000	7,000,000	$ 4,000,000
Amount claimed from over payments of legal settlements due to change in calculations					2,000,000
McAllen Medical Center
Commitments and Contingencies Disclosure [Line Items]
Amount awarded to plaintiff	3,850,000
Total amount of order, including prejudgment interest	9,000,000
DOJ
Commitments and Contingencies Disclosure [Line Items]
Increase in aggregate pre-tax reserve	123,000,000		22,000,000
Pre-tax increase to reserve for civil aspects	102,000,000
River Point Behavioral Health
Commitments and Contingencies Disclosure [Line Items]
Amount withheld in contingent medicare payment suspension								9,000,000
Construction Commitment
Commitments and Contingencies Disclosure [Line Items]
Combined estimated future purchase obligations	55,000,000							55,000,000
Revenue Cycle Data Processing Services
Commitments and Contingencies Disclosure [Line Items]
Combined estimated future purchase obligations	57,000,000							57,000,000
Electronic Health Records And Revenue Cycle Application
Commitments and Contingencies Disclosure [Line Items]
Combined estimated future purchase obligations	194,000,000							194,000,000
Estimated Minimum Liabilities For Physician Commitments
Commitments and Contingencies Disclosure [Line Items]
Combined estimated future purchase obligations	2,000,000							2,000,000
Related to Certain Equipment
Commitments and Contingencies Disclosure [Line Items]
Combined estimated future purchase obligations	201,000,000							201,000,000
Commercial Health Insurer and Self-insured Employee Benefit Plans
Commitments and Contingencies Disclosure [Line Items]
Combined estimated future purchase obligations	78,000,000							78,000,000
Wind Storms
Commitments and Contingencies Disclosure [Line Items]
Minimum Insurance Deductible	50,000							50,000
Maximum insurance deductible	250,000							250,000
Flood
Commitments and Contingencies Disclosure [Line Items]
Maximum insurance deductible	500,000							500,000
Professional And General Liability
Commitments and Contingencies Disclosure [Line Items]
Increase in professional and general liability self-insurance reserves relating to prior years			15,000,000
Pennsylvania | Department of Human Services
Commitments and Contingencies Disclosure [Line Items]
Number of behavioral health care hospitals | Hospital							7
Cygnet Health Care Limited
Commitments and Contingencies Disclosure [Line Items]
Property insurance | £		£ 1,290
Maximum | Wind Storms
Commitments and Contingencies Disclosure [Line Items]
Commercial property insurance policies covering catastrophic losses	$ 1,000,000,000							$ 1,000,000,000
Percentage of insurance deductible	5.00%							5.00%
Maximum | LAS VEGAS, NEVADA | Earthquake
Commitments and Contingencies Disclosure [Line Items]
Commercial property insurance policies covering catastrophic losses	$ 500,000,000							$ 500,000,000
Maximum | CALIFORNIA | Earthquake
Commitments and Contingencies Disclosure [Line Items]
Commercial property insurance policies covering catastrophic losses	130,000,000							130,000,000
Maximum | PUERTO RICO | Earthquake
Commitments and Contingencies Disclosure [Line Items]
Commercial property insurance policies covering catastrophic losses	40,000,000							40,000,000
Maximum | OTHER STATES | Earthquake
Commitments and Contingencies Disclosure [Line Items]
Commercial property insurance policies covering catastrophic losses	250,000,000							250,000,000
Maximum | Faulty Zones of UNITED STATES | Earthquake
Commitments and Contingencies Disclosure [Line Items]
Commercial property insurance policies covering catastrophic losses	$ 100,000,000							$ 100,000,000
Minimum | Wind Storms
Commitments and Contingencies Disclosure [Line Items]
Percentage of insurance deductible	3.00%							3.00%
General and Professional Liability
Commitments and Contingencies Disclosure [Line Items]
Self-insured for professional and general liability	$ 243,051,000		$ 228,691,000					$ 243,051,000			207,459,000	203,973,000
Subsidiaries | Professional Liability | Cygnet Health Care Limited
Commitments and Contingencies Disclosure [Line Items]
Self-insured for professional and general liability | £										£ 10
Subsidiaries | Professional Liability | Maximum
Commitments and Contingencies Disclosure [Line Items]
Self-insured for professional and general liability									$ 5,000,000		10,000,000
Subsidiaries | General Liability | Cygnet Health Care Limited
Commitments and Contingencies Disclosure [Line Items]
Self-insured for professional and general liability | £										£ 25
Subsidiaries | General Liability | Maximum
Commitments and Contingencies Disclosure [Line Items]
Self-insured for professional and general liability									$ 3,000,000		3,000,000
Subsidiaries | General And Professional Liability Insurance Policies
Commitments and Contingencies Disclosure [Line Items]
Percentage of liability for claims paid under commercially insured coverage	10.00%							10.00%
Subsidiaries | General And Professional Liability Insurance Policies | Maximum
Commitments and Contingencies Disclosure [Line Items]
Purchased several excess policies through commercial insurance carriers per occurrence				$ 250,000,000	$ 200,000,000						$ 250,000,000	$ 250,000,000
Liability for claims paid under commercially insured coverage	$ 5,000,000							$ 5,000,000
Subsidiaries | General And Professional Liability Insurance Policies | Maximum | Located in U.K.
Commitments and Contingencies Disclosure [Line Items]
Liability for claims paid under commercially insured coverage	$ 8,500,000							$ 8,500,000