Basis of Presentation and Significant Accounting Policies - Additional Information (Details)			1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended	14 Months Ended
	May 01, 2020 Item	Jan. 01, 2020 Item	Apr. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)	Jun. 30, 2021 USD ($)
Cost of Revenue, Policy [Abstract]
Corporate office costs				$ 52,000,000	$ 57,000,000	$ 112,000,000	$ 95,000,000
Third Party Reimbursement [Abstract]
Amounts due to third party payors				112,000,000		112,000,000		$ 98,000,000	$ 112,000,000
Amounts due from third party payors				111,000,000		111,000,000		136,000,000	111,000,000
Net Operating Revenues, Policy [Abstract]
Charity care services charges excluded from net operating revenues				215,000,000	138,000,000	444,000,000	304,000,000
Value of charity care services at the Company's standard charges included in contractual allowances				26,000,000	17,000,000	52,000,000	36,000,000
Accounting for the Impairment or Disposal of Long-Lived Assets
Gain (loss) on disposition of business						(23,000,000)	(56,000,000)
Impairment of long-lived assets sold						28,000,000
Impairment of long-lived assets held for sale							64,000,000
Divestiture related expenses						3,000,000
Goodwill allocated to facilities disposed of				7,000,000		7,000,000			7,000,000
CARES Act
Medicare Accelerated Payments [Abstract]
Medicare accelerated payments received under the Cares Act			$ 1,200,000,000	0		0
Medicare accelerated payments, recouped subject to the aforementioned repayment terms				116,000,000		116,000,000			116,000,000
CARES Act | Long-term Liability
Medicare Accelerated Payments [Abstract]
Medicare accelerated outstanding estimated amount under cares act				267,000,000		267,000,000			267,000,000
CARES Act | Accrued Liabilities and Other
Medicare Accelerated Payments [Abstract]
Medicare accelerated payments under cares act				680,000,000		680,000,000			680,000,000
CARES Act | Centers for Medicare & Medicaid Services
Medicare Accelerated Payments [Abstract]
Medicare accelerated repayment under cares act						$ 18,000,000		77,000,000
Medicare accelerated percentage of repayment will occur through an automatic recoupment						25.00%
Medicare accelerated percentage of recoupment will increase						50.00%
Medicare accelerated payments interest rate from the date letter was issued						4.00%
CARES Act | Paycheck Protection Program and Health Care Enhancement Act
COVID-19 Pandemic [Abstract]
Percentage of maximum accelerated payment						100.00%
Medicare accelerated and advance payment program period						6 months
Public Health and Social Services Emergency Fund (the "PHSSEF") | CARES Act | Paycheck Protection Program and Health Care Enhancement Act
COVID-19 Pandemic [Abstract]
CARES Act, PPPHCE Act of 2020 Aid, amount, CAA and ARPA						$ 178,000,000,000
CARES Act and PPPHCE Act Funds [Abstract]
Payments through the PHSSEF and various state and local programs								705,000,000	$ 712,000,000
Public Health and Social Services Emergency Fund (the "PHSSEF") | CARES Act | Paycheck Protection Program and Health Care Enhancement Act | Operating Costs and Expenses
CARES Act and PPPHCE Act Funds [Abstract]
Payments through the PHSSEF and various state and local programs				$ 1,000,000	$ 448,000,000	83,000,000	448,000,000	$ 601,000,000
Hospitals Sold or Deemed Held for Sale
Accounting for the Impairment or Disposal of Long-Lived Assets
Gain (loss) on disposition of business						$ 8,000,000	21,000,000
Number of hospitals sold | Item	2	3
Hospitals Sold or Deemed Held for Sale | Certain Hospitals
Accounting for the Impairment or Disposal of Long-Lived Assets
Gain (loss) on disposition of business							$ (13,000,000)