Accounting Policies - Additional Information (Detail)		12 Months Ended			204 Months Ended
	Oct. 31, 2017	Dec. 31, 2017 USD ($) Claim State Hospital Surgery_Center	Dec. 31, 2016 USD ($) Claim	Dec. 31, 2015 USD ($)	Dec. 31, 2017 USD ($) Claim State Hospital Surgery_Center
Summary Of Significant Accounting Policies [Line Items]
Number of owned and operated hospitals | Hospital		179			179
Number of freestanding surgery centers | Surgery_Center		120			120
Number of facilities locations | State		20			20
General and administrative expense		$ 373,000,000	$ 373,000,000	$ 327,000,000
Adjustments to estimated reimbursement filed during respective year		41,000,000	31,000,000	48,000,000
Adjustments to estimated reimbursement filed during previous years		$ 56,000,000	$ 90,000,000	$ 85,000,000
Percentage of the sum of revenues, uninsured discounts and charity care		34.90%	33.00%	31.50%
Outstanding checks unpresented for payment		$ 480,000,000	$ 565,000,000		$ 480,000,000
Allowance for doubtful accounts percentage of accounts receivable		100.00%	98.00%
Allowance for doubtful accounts		$ 5,488,000,000	$ 5,116,000,000		5,488,000,000
Days revenues in accounts receivable		52 days	50 days	53 days
Depreciation expense		$ 2,111,000,000	$ 1,946,000,000	$ 1,880,000,000
Goodwill impairments		0	0	0	102,000,000
Goodwill acquired during period		693,000,000	41,000,000
Intangible assets decreased		15,000,000	19,000,000
Gross carrying amount of intangible assets		184,000,000	184,000,000
Accumulated amortization of intangible assets		94,000,000	79,000,000		94,000,000
Gross carrying amount of indefinite-lived intangible assets		269,000,000	269,000,000		269,000,000
Deferred loan costs		353,000,000	334,000,000		353,000,000
Deferred loan costs, accumulated amortization		189,000,000	164,000,000		189,000,000
Amortization of debt issuance costs		31,000,000	34,000,000	35,000,000
Reserves for professional liability risks		1,627,000,000	1,539,000,000		1,627,000,000
Current portion of professional liability risks reserves		429,000,000	391,000,000		$ 429,000,000
Provisions for losses related to professional liability risks		$ 466,000,000	$ 430,000,000	$ 344,000,000
Reserves for professional liability risks cover individual claims | Claim		2,500	2,700		2,500
Net payments of professional and general liability claims		$ 357,000,000	$ 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		19,000,000	36,000,000		$ 19,000,000
Amounts receivable under reinsurance contracts recorded in other current assets		$ 5,000,000	9,000,000		$ 5,000,000
Insurance Subsidiary [Member]
Summary Of Significant Accounting Policies [Line Items]
Insurance subsidiary ownership percentage		100.00%			100.00%
Sales, Foreign Currency Translation and Other [Member]
Summary Of Significant Accounting Policies [Line Items]
Goodwill increase (decrease)			$ (49,000,000)
Foreign Currency Translation And Other [Member]
Summary Of Significant Accounting Policies [Line Items]
Goodwill increase (decrease)		$ 12,000,000
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] | 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