Accounting Policies - Schedule of Estimated Cost of Uncompensated Care (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Patient care costs (salaries and benefits, supplies, other operating expenses and depreciation and amortization)	$ 55,341	$ 51,180	$ 49,074
Cost-to-charges ratio (patient care costs as percentage of gross patient charges)	10.50%	11.00%	11.30%
Total uncompensated care	$ 35,426	$ 31,734	$ 29,642
Multiply by the cost-to-charges ratio	10.50%	11.00%	11.30%
Estimated cost of total uncompensated care	$ 3,720	$ 3,491	$ 3,350