Basis of Presentation and Significant Accounting Policies (Narrative) (Details) $ in Millions		3 Months Ended
	Jan. 01, 2020 item	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)
Net Operating Revenues, Policy [Abstract]
Value of charity care services at the Company's standard charges included in contractual allowances		$ 166	$ 141
Estimated cost incurred by Company to provide charity care services		19	15
Third-Party Reimbursement [Abstract]
Amounts due to third party payors		87		$ 83
Amounts due from third party payors		131		$ 137
Accounting for the Impairment or Disposal of Long-Lived Assets
Gain (loss) on disposition of business		45
Impairment and gain (loss) on sale of businesses, net		45	38
Goodwill allocated to hospital disposal group held for sale		6
Cost of Revenue [Abstract]
Corporate office costs		37	43
Stock-based compensation expense		2	3
Hospitals Sold or Deemed Held for Sale [Member]
Accounting for the Impairment or Disposal of Long-Lived Assets
Gain (loss) on disposition of business		19	$ 38
Number of hospitals sold | item	3
Adjustment for Carrying Value of Other Long-Lived Assets at Underperforming Hospitals [Member]
Accounting for the Impairment or Disposal of Long-Lived Assets
Impairment and gain (loss) on sale of businesses, net		$ 64