Consolidated Income Statements - USD ($) shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Revenues	$ 12,274	$ 11,451	$ 11,529	$ 11,423	$ 11,562	$ 10,696	$ 10,733	$ 10,623	$ 46,677	$ 43,614	$ 41,490
Salaries and benefits									21,425	20,059	18,897
Supplies									7,724	7,316	6,933
Other operating expenses									8,608	8,051	7,496
Equity in earnings of affiliates									(29)	(45)	(54)
Depreciation and amortization									2,278	2,131	1,966
Interest expense									1,755	1,690	1,707
Gains on sales of facilities									(428)	(8)	(23)
Losses on retirement of debt									9	39	4
Legal claim benefits											(246)
Total expenses including equity in earnings of affiliates									41,342	39,233	36,680
Income before income taxes									5,335	4,381	4,810
Provision for income taxes									946	1,638	1,378
Net income	1,245	896	966	1,282	641	530	795	777	4,389	2,743	3,432
Net income attributable to noncontrolling interests									602	527	542
Net income attributable to HCA Healthcare, Inc.	$ 1,064	$ 759	$ 820	$ 1,144	$ 474	$ 426	$ 657	$ 659	$ 3,787	$ 2,216	$ 2,890
Per share data:
Basic earnings per share	$ 3.09	$ 2.20	$ 2.35	$ 3.26	$ 1.34	$ 1.18	$ 1.79	$ 1.78	$ 10.90	$ 6.12	$ 7.53
Diluted earnings per share	$ 3.01	$ 2.15	$ 2.31	$ 3.18	$ 1.30	$ 1.15	$ 1.75	$ 1.74	$ 10.66	$ 5.95	$ 7.30
Shares used in earnings per share calculations (in millions):
Basic									347,297	362,305	383,591
Diluted									355,303	372,221	395,851