Earnings Per Share - Schedule of Computations of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Earnings Per Share [Abstract]
Net income attributable to HCA Healthcare, Inc.	$ 1,591	$ 1,363
Weighted average common shares outstanding	264,435	276,910
Effect of dilutive incremental shares	3,581	4,051
Shares used for diluted earnings per share	268,016	280,961
Basic earnings	$ 6.01	$ 4.92
Diluted earnings	$ 5.93	$ 4.85