Accounting Policies - Additional Information (Detail)			1 Months Ended	12 Months Ended
	Oct. 01, 2018 USD ($)	Oct. 31, 2017	Nov. 30, 2017	Dec. 31, 2018 USD ($) Claim State Hospital Surgery_Center	Dec. 31, 2017 USD ($) Claim	Dec. 31, 2016 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of owned and operated hospitals | Hospital				179
Number of freestanding surgery centers | Surgery_Center				123
Number of facilities locations | State				20
General and administrative expense				$ 344,000,000	$ 340,000,000	$ 343,000,000
Adjustments to estimated reimbursement filed during respective year				29,000,000	41,000,000	31,000,000
Adjustments to estimated reimbursement filed during previous years				51,000,000	56,000,000	$ 90,000,000
Estimated implicit price concessions recorded as reductions to revenues and accounts receivable				$ 6,280,000,000	$ 5,488,000,000
Percentage of sum of revenues and uncompensated care				36.40%	34.90%	33.00%
Charity care amount				$ 8,611,000,000	$ 4,861,000,000	$ 4,151,000,000
Estimated costs of charity care				1,068,000	627,000,000	$ 560,000,000
Outstanding checks unpresented for payment				$ 449,000,000	$ 480,000,000
Days revenues in accounts receivable				51 days	52 days	50 days
Depreciation expense				$ 2,262,000,000	$ 2,111,000,000	$ 1,946,000,000
Goodwill impairments				0	0	0
Goodwill acquired during period				636,000,000	693,000,000
Intangible assets decreased				17,000,000	15,000,000
Gross carrying amount of intangible assets				184,000,000	184,000,000
Accumulated amortization of intangible assets				111,000,000	94,000,000
Gross carrying amount of indefinite-lived intangible assets				269,000,000	269,000,000
Deferred loan costs				360,000,000	353,000,000
Deferred loan costs, accumulated amortization				203,000,000	189,000,000
Amortization of debt issuance costs				31,000,000	31,000,000	34,000,000
Reserves for professional liability risks				1,741,000,000	1,627,000,000
Current portion of professional liability risks reserves				466,000,000	429,000,000
Provisions for losses related to professional liability risks				447,000,000	$ 466,000,000	$ 430,000,000
Decrease in provision for professional liability risks				$ (70,000,000)
Reserves for professional liability risks cover individual claims | Claim				2,200	2,500
Net payments of professional and general liability claims				$ 358,000,000	$ 357,000,000
Self-insured retention amount per occurrence				15,000,000
Maximum amount losses per occurrence				50,000,000
Reinsurance for professional liability risks retention level of amount per occurrence				25,000,000
Amounts receivable under reinsurance contracts recorded in other assets				40,000,000	19,000,000
Amounts receivable under reinsurance contracts recorded in other current assets				10,000,000	5,000,000
Foreign Currency Translation And Other [Member]
Summary Of Significant Accounting Policies [Line Items]
Goodwill increase (decrease)				$ (60,000,000)	$ 12,000,000
Insurance Subsidiary [Member]
Summary Of Significant Accounting Policies [Line Items]
Insurance subsidiary ownership percentage				100.00%
Inpatient Services [Member]
Summary Of Significant Accounting Policies [Line Items]
Performance obligations for inpatient/ outpatient services satisfied period				Our performance obligations for inpatient services are generally satisfied over periods that average approximately five days
Accounting Standards Update 2018-02 [Member]
Summary Of Significant Accounting Policies [Line Items]
Reclassification of stranded tax effects	$ 95,000,000
Accounting Standards Update 2016-02 [Member]
Summary Of Significant Accounting Policies [Line Items]
Expected amount of right-of-use assets and obligations				$ 1,600,000,000
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of income of federal poverty level eligible for charity care		200.00%	400.00%
Finite lived intangible asset useful life				10 years
Maximum [Member] | Outpatient Services [Member]
Summary Of Significant Accounting Policies [Line Items]
Performance obligations for inpatient/ outpatient services satisfied period				Our performance obligations for outpatient services are generally satisfied over a period of less than one day
Maximum [Member] | Building and Improvements [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives in years				40 years
Maximum [Member] | Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives in years				10 years
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of income of federal poverty level eligible for charity care			200.00%
Finite lived intangible asset useful life				3 years
Minimum [Member] | Building and Improvements [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives in years				10 years
Minimum [Member] | Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives in years				4 years