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, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Earnings Per Share [Abstract]
Net income attributable to HCA Healthcare, Inc.	$ 1,270	$ 1,079	$ 4,322	$ 3,635
Weighted average common shares outstanding	256,763	271,173	260,770	274,171
Effect of dilutive incremental shares	3,154	4,251	3,217	4,002
Shares used for diluted earnings per share	259,917	275,424	263,987	278,173
Basic earnings per share	$ 4.94	$ 3.98	$ 16.57	$ 13.26
Diluted earnings per share	$ 4.88	$ 3.91	$ 16.37	$ 13.07