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		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share [Abstract]
Net income attributable to HCA Healthcare, Inc.	$ 1,079	$ 1,134	$ 3,635	$ 3,562
Weighted average common shares outstanding	271,173	285,958	274,171	293,583
Effect of dilutive incremental shares	4,251	3,894	4,002	4,119
Shares used for diluted earnings per share	275,424	289,852	278,173	297,702
Basic earnings per share	$ 3.98	$ 3.97	$ 13.26	$ 12.13
Diluted earnings per share	$ 3.91	$ 3.91	$ 13.07	$ 11.97