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		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Earnings Per Share [Abstract]
Net income attributable to HCA Healthcare, Inc.	$ 1,193	$ 1,155	$ 2,556	$ 2,428
Weighted average common shares outstanding	274,494	292,527	275,695	297,459
Effect of dilutive incremental shares	3,704	3,534	3,878	4,231
Shares used for diluted earnings per share	278,198	296,061	279,573	301,690
Basic earnings per share	$ 4.35	$ 3.95	$ 9.27	$ 8.16
Diluted earnings per share	$ 4.29	$ 3.9	$ 9.14	$ 8.05