Basis of Presentation and Significant Accounting Policies - Schedule of Net Operating Revenues (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Net operating revenues	$ 2,519	$ 3,302	$ 5,544	$ 6,679
Medicare
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Net operating revenues	607	819	1,363	1,708
Medicaid
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Net operating revenues	341	452	748	880
Managed Care and Other Third Party Payors
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Net operating revenues	1,626	1,993	3,458	4,019
Self-Pay
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Net operating revenues	$ (55)	$ 38	$ (25)	$ 72