Supplemental Condensed Consolidating Financial Information and Other Collateral-Related Information - Schedule of Condensed Consolidating Comprehensive Income Statement (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Condensed Statement of Income Captions [Line Items]
Revenues before provision for doubtful accounts	$ 11,806	$ 11,081	$ 23,189	$ 22,131
Provision for doubtful accounts	1,073	762	1,833	1,552
Revenues	10,733	10,319	21,356	20,579
Salaries and benefits	4,896	4,691	9,797	9,393
Supplies	1,795	1,718	3,592	3,432
Other operating expenses	1,965	1,868	3,895	3,721
Equity in earnings of affiliates	(13)	(10)	(23)	(22)
Depreciation and amortization	521	489	1,042	968
Interest expense	411	427	830	843
Gains on sales of facilities	(2)	(6)	(3)	(5)
Legal claim costs		10		22
Total expenses including equity in earnings of affiliates	9,573	9,187	19,130	18,352
Income (loss) before income taxes	1,160	1,132	2,226	2,227
Provision (benefit) for income taxes	365	341	654	625
Net income (loss)	795	791	1,572	1,602
Net income attributable to noncontrolling interests	138	133	256	250
Net income (loss) attributable to HCA Healthcare, Inc.	657	658	1,316	1,352
Comprehensive income (loss) attributable to HCA Healthcare, Inc.	684	608	1,361	1,273
HCA Healthcare, Inc. Issuer [Member]
Condensed Statement of Income Captions [Line Items]
Other operating expenses	4	2	5	4
Equity in earnings of affiliates	(658)	(641)	(1,266)	(1,270)
Interest expense	16	16	32	32
Total expenses including equity in earnings of affiliates	(638)	(623)	(1,229)	(1,234)
Income (loss) before income taxes	638	623	1,229	1,234
Provision (benefit) for income taxes	(19)	(35)	(87)	(118)
Net income (loss)	657	658	1,316	1,352
Net income (loss) attributable to HCA Healthcare, Inc.	657	658	1,316	1,352
Comprehensive income (loss) attributable to HCA Healthcare, Inc.	684	608	1,361	1,273
HCA Inc. Issuer [Member]
Condensed Statement of Income Captions [Line Items]
Interest expense	755	670	1,488	1,320
Legal claim costs		10		22
Total expenses including equity in earnings of affiliates	755	680	1,488	1,342
Income (loss) before income taxes	(755)	(680)	(1,488)	(1,342)
Provision (benefit) for income taxes	(279)	(251)	(549)	(495)
Net income (loss)	(476)	(429)	(939)	(847)
Net income (loss) attributable to HCA Healthcare, Inc.	(476)	(429)	(939)	(847)
Comprehensive income (loss) attributable to HCA Healthcare, Inc.	(480)	(431)	(936)	(856)
Subsidiary Guarantors [Member]
Condensed Statement of Income Captions [Line Items]
Revenues before provision for doubtful accounts	6,049	5,693	11,902	11,366
Provision for doubtful accounts	593	498	1,012	992
Revenues	5,456	5,195	10,890	10,374
Salaries and benefits	2,437	2,347	4,903	4,701
Supplies	931	886	1,882	1,784
Other operating expenses	951	893	1,878	1,750
Equity in earnings of affiliates	(1)	(1)	(2)	(3)
Depreciation and amortization	248	238	499	465
Interest expense	(291)	(204)	(560)	(411)
Gains on sales of facilities	(1)	(2)	(1)
Management fees	(212)	(235)	(422)	(395)
Total expenses including equity in earnings of affiliates	4,062	3,922	8,177	7,891
Income (loss) before income taxes	1,394	1,273	2,713	2,483
Provision (benefit) for income taxes	505	462	983	900
Net income (loss)	889	811	1,730	1,583
Net income attributable to noncontrolling interests	27	21	50	43
Net income (loss) attributable to HCA Healthcare, Inc.	862	790	1,680	1,540
Comprehensive income (loss) attributable to HCA Healthcare, Inc.	865	794	1,686	1,546
Subsidiary Non-Guarantors [Member]
Condensed Statement of Income Captions [Line Items]
Revenues before provision for doubtful accounts	5,757	5,388	11,287	10,765
Provision for doubtful accounts	480	264	821	560
Revenues	5,277	5,124	10,466	10,205
Salaries and benefits	2,459	2,344	4,894	4,692
Supplies	864	832	1,710	1,648
Other operating expenses	1,010	973	2,012	1,967
Equity in earnings of affiliates	(12)	(9)	(21)	(19)
Depreciation and amortization	273	251	543	503
Interest expense	(69)	(55)	(130)	(98)
Gains on sales of facilities	(1)	(4)	(2)	(5)
Management fees	212	235	422	395
Total expenses including equity in earnings of affiliates	4,736	4,567	9,428	9,083
Income (loss) before income taxes	541	557	1,038	1,122
Provision (benefit) for income taxes	158	165	307	338
Net income (loss)	383	392	731	784
Net income attributable to noncontrolling interests	111	112	206	207
Net income (loss) attributable to HCA Healthcare, Inc.	272	280	525	577
Comprehensive income (loss) attributable to HCA Healthcare, Inc.	300	228	561	501
Eliminations [Member]
Condensed Statement of Income Captions [Line Items]
Equity in earnings of affiliates	658	641	1,266	1,270
Total expenses including equity in earnings of affiliates	658	641	1,266	1,270
Income (loss) before income taxes	(658)	(641)	(1,266)	(1,270)
Net income (loss)	(658)	(641)	(1,266)	(1,270)
Net income (loss) attributable to HCA Healthcare, Inc.	(658)	(641)	(1,266)	(1,270)
Comprehensive income (loss) attributable to HCA Healthcare, Inc.	$ (685)	$ (591)	$ (1,311)	$ (1,191)