Basis of Presentation and Significant Accounting Policies - Additional Information (Details)				1 Months Ended	3 Months Ended		6 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($)	Jul. 01, 2020 Item	Jan. 01, 2020 Item	Apr. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Jul. 02, 2020 USD ($)	Jun. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Cost of Revenue [Abstract]
Corporate office costs					$ 41,000,000	$ 48,000,000			$ 136,000,000	$ 135,000,000
Stock-based compensation expense					3,000,000	2,000,000			8,000,000	8,000,000
Third-Party Reimbursement [Abstract]
Amounts due to third party payors	$ 94,000,000				94,000,000				94,000,000		$ 83,000,000
Amounts due from third party payors	124,000,000				124,000,000				124,000,000		$ 137,000,000
Net Operating Revenues, Policy [Abstract]
Charity care services charges excluded from net operating revenues					285,000,000	126,000,000			751,000,000	410,000,000
Accounting for the Impairment or Disposal of Long-Lived Assets
Gain (loss) on disposition of business									(48,000,000)	(70,000,000)
Goodwill allocated to hospital disposal group held for sale	$ 109,000,000				$ 109,000,000	68,000,000			$ 109,000,000	68,000,000
Medicare Accelerated Payments [Abstract]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true				true				true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Mar. 12, 2020				Mar. 12, 2020				Mar. 12, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true				true				true
Accounting Standards Update [Extensible List]									cyh:AccountingStandardsUpdate202004Member
CARES Act
Medicare Accelerated Payments [Abstract]
Medicare accelerated payments received under the Cares Act				$ 1,200,000,000	$ 0
Medicare accelerated payments period									1 year
CARES Act | Long-term Liability
Medicare Accelerated Payments [Abstract]
Medicare accelerated outstanding estimated amount under cares act	$ 873,000,000				873,000,000				$ 873,000,000
CARES Act | Accrued Liabilities and Other
Medicare Accelerated Payments [Abstract]
Medicare accelerated payments under cares act	1,100,000,000				1,100,000,000				$ 1,100,000,000
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 and PPPHCE Act of 2020 Aid, amount									$ 175,000,000,000
CARES Act and PPPHCE Act Funds [Abstract]
Accelerated payments received under the Cares Act									719,000,000
Estimated decrease in relief funds recognized under Cares Act								$ 66,000,000
Relief funds recognized					448,000,000				448,000,000
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]
Accelerated payments received under the Cares Act					155,000,000			$ 448,000,000	448,000,000
Hospitals Closed
Accounting for the Impairment or Disposal of Long-Lived Assets
Gain (loss) on disposition of business	$ (3,000,000)
Hospitals Sold or Deemed Held for Sale
Accounting for the Impairment or Disposal of Long-Lived Assets
Gain (loss) on disposition of business							$ 73,000,000		(43,000,000)
Number of hospitals sold | Item		1	3
Adjustment for Carrying Value of Other Long-Lived Assets at Underperforming Hospitals
Accounting for the Impairment or Disposal of Long-Lived Assets
Impairment and gain (loss) on sale of businesses, net									74,000,000
Shared Service Center
Accounting for the Impairment or Disposal of Long-Lived Assets
Gain (loss) on disposition of business									(1,000,000)
Health Care, Patient Service
Net Operating Revenues, Policy [Abstract]
Value of charity care services at the Company's standard charges included in contractual allowances					36,000,000	$ 16,000,000			90,000,000	$ 50,000,000
Centers for Medicare & Medicaid Services | CARES Act
Medicare Accelerated Payments [Abstract]
Medicare accelerated repayment under cares act					22,000,000
Medicare accelerated payments recouped under cares act					$ 0				$ 0
Medicare accelerated payment recouped description									As of September 30, 2020, the program required CMS to begin recouping payments 120 days after receipt by the provider although no payments were recouped during the three or nine months ended September 30, 2020. Effective October 1, 2020, the program was amended such that providers are required to repay accelerated payments beginning one year after the payment was issued. After such one-year period, Medicare payments owed to providers will be recouped according to the repayment terms. The repayment terms specify that for the first 11 months after repayment begins, repayment will occur through an automatic recoupment of 25% of Medicare payments otherwise owed to the provider. At the end of the eleven-month period, recoupment will increase to 50% for six months. At the end of the six months (29 months from the receipt of the initial accelerated payment), Medicare will issue a letter for full repayment of any remaining balance, as applicable. In such event, if payment is not received within 30 days, interest will accrue at the annual percentage rate of four percent (4%) from the date the letter was issued, and will be assessed for each full 30-day period that the balance remains unpaid.
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%