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, 2023	Mar. 31, 2022
Earnings Per Share [Abstract]
Net income attributable to HCA Healthcare, Inc.	$ 1,363	$ 1,273
Weighted average common shares outstanding	276,910	302,446
Effect of dilutive incremental shares	4,051	4,928
Shares used for diluted earnings per share	280,961	307,374
Basic earnings per share	$ 4.92	$ 4.21
Diluted earnings per share	$ 4.85	$ 4.14