Basis of Presentation and Significant Accounting Policies - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2021 USD ($) State Hospital Surgery_Center Endoscopy_Center	Mar. 31, 2020 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of owned and operated hospitals | Hospital	186
Number of freestanding surgery centers | Surgery_Center	121
Number of freestanding endoscopy centers | Endoscopy_Center	21
Number of facilities locations | State	20
General and administrative expense	$ 87	$ 96
Performance obligations for inpatient/ outpatient services satisfied period	Our performance obligations for outpatient services are generally satisfied over a period of less than one day.
Charity care amount	$ 2,942	3,735
Estimated costs of charity care	335	$ 444
Out of Network Services [Member]
Summary Of Significant Accounting Policies [Line Items]
Revenues	$ 55
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of income of federal poverty level eligible for charity care	400.00%