Commitments and Contingencies - Additional Information (Detail) £ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2020 GBP (£)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 GBP (£)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2010 USD ($)
Commitments and Contingencies Disclosure [Line Items]
Self-insured for professional and general liability	$ 368,964,000									$ 322,824,000	$ 314,941,000	$ 298,222,000
Self-insured for professional and general liability, current	74,000,000									42,000,000	42,000,000
Compensation liability claims	105,000,000									81,000,000	72,000,000
Compensation and related benefits	55,000,000									40,000,000	40,000,000
Combined estimated future purchase obligations	349,000,000
Defined benefit pension plan estimated payments through 2089	159,000,000
Other retirement plan liabilities	22,000,000
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	$ 4,000,000
Amount claimed from over payments of legal settlements			7,000,000	8,000,000	7,000,000	4,000,000
Amount claimed from over payments of legal settlements due to change in calculations			3,000,000	2,000,000	2,000,000
Construction Commitment
Commitments and Contingencies Disclosure [Line Items]
Combined estimated future purchase obligations	95,000,000
Revenue Cycle Data Processing Services
Commitments and Contingencies Disclosure [Line Items]
Combined estimated future purchase obligations	27,000,000
Electronic Health Records And Revenue Cycle Application
Commitments and Contingencies Disclosure [Line Items]
Combined estimated future purchase obligations	218,000,000
Other Software Applications
Commitments and Contingencies Disclosure [Line Items]
Combined estimated future purchase obligations	29,000,000
Related to Certain Equipment
Commitments and Contingencies Disclosure [Line Items]
Combined estimated future purchase obligations	181,000,000
Commercial Health Insurer and Self-insured Employee Benefit Plans
Commitments and Contingencies Disclosure [Line Items]
Combined estimated future purchase obligations	91,000,000
Healthcare Infrastructure
Commitments and Contingencies Disclosure [Line Items]
Combined estimated future purchase obligations	75,000,000
Wind Storms
Commitments and Contingencies Disclosure [Line Items]
Maximum insurance deductible	2,500,000
Cygnet Health Care Limited
Commitments and Contingencies Disclosure [Line Items]
Property insurance | £		£ 1,500
Maximum | Wind Storms
Commitments and Contingencies Disclosure [Line Items]
Commercial property insurance policies covering catastrophic losses	$ 1,000,000,000
Percentage of insurance deductible	5.00%								5.00%
Maximum | Earthquake | LAS VEGAS, NEVADA
Commitments and Contingencies Disclosure [Line Items]
Commercial property insurance policies covering catastrophic losses	$ 300,000,000
Maximum | Earthquake | CALIFORNIA
Commitments and Contingencies Disclosure [Line Items]
Commercial property insurance policies covering catastrophic losses	130,000,000
Maximum | Earthquake | OTHER STATES
Commitments and Contingencies Disclosure [Line Items]
Commercial property insurance policies covering catastrophic losses	250,000,000
Maximum | Earthquake | Faulty Zones of UNITED STATES
Commitments and Contingencies Disclosure [Line Items]
Commercial property insurance policies covering catastrophic losses	100,000,000
Maximum | Earthquake | PUERTO RICO
Commitments and Contingencies Disclosure [Line Items]
Commercial property insurance policies covering catastrophic losses	40,000,000
Maximum | Flood
Commitments and Contingencies Disclosure [Line Items]
Commercial property insurance policies covering catastrophic losses	100,000,000
Maximum | Flood | Texas
Commitments and Contingencies Disclosure [Line Items]
Commercial property insurance policies covering catastrophic losses	10,000,000
Maximum | Flood | PUERTO RICO
Commitments and Contingencies Disclosure [Line Items]
Commercial property insurance policies covering catastrophic losses	$ 1,000,000
Minimum | Wind Storms
Commitments and Contingencies Disclosure [Line Items]
Percentage of insurance deductible	3.00%								3.00%
General And Professional Liability Insurance Policies
Commitments and Contingencies Disclosure [Line Items]
Self-insured for professional and general liability	$ 25,000,000
General and Professional Liability
Commitments and Contingencies Disclosure [Line Items]
Self-insured for professional and general liability	263,779,000									241,820,000	243,051,000	228,691,000
Workers’ Compensation Liability Insurance Policies
Commitments and Contingencies Disclosure [Line Items]
Self-insured for professional and general liability	20,000,000
Subsidiaries | Professional Liability
Commitments and Contingencies Disclosure [Line Items]
Purchased several excess policies through commercial insurance carriers per occurrence	2,500,000
Purchased several excess policies through commercial insurance carriers per occurrence excess claim amount	10,000,000
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	10,000,000									5,000,000	5,000,000	5,000,000	$ 10,000,000
Subsidiaries | Professional Liability | Maximum | Forecast
Commitments and Contingencies Disclosure [Line Items]
Self-insured for professional and general liability								$ 20,000,000
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	3,000,000	3,000,000	3,000,000
Subsidiaries | General Liability | Maximum | Forecast
Commitments and Contingencies Disclosure [Line Items]
Self-insured for professional and general liability								3,000,000
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		$ 250,000,000	$ 250,000,000	$ 200,000,000	$ 200,000,000	$ 200,000,000			$ 250,000,000	$ 250,000,000	$ 250,000,000	$ 250,000,000	$ 200,000,000
Subsidiaries | General And Professional Liability Insurance Policies | Maximum | Forecast
Commitments and Contingencies Disclosure [Line Items]
Purchased several excess policies through commercial insurance carriers per occurrence								$ 155,000,000