Supplemental Condensed Consolidating Financial Information and Other Collateral-Related Information - Schedule of Condensed Consolidating Comprehensive Income Statement (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplemental Condensed Consolidating Financial Information [Line Items]
Revenues before provision for doubtful accounts									$ 44,747	$ 43,591	$ 40,087
Provision for doubtful accounts									3,257	3,913	3,169
Revenues	$ 10,641	$ 10,270	$ 10,319	$ 10,260	$ 10,249	$ 9,856	$ 9,897	$ 9,676	41,490	39,678	36,918
Salaries and benefits									18,897	18,115	16,641
Supplies									6,933	6,638	6,262
Other operating expenses									7,508	7,103	6,755
Electronic health record incentive income									(12)	(47)	(125)
Equity in earnings of affiliates									(54)	(46)	(43)
Depreciation and amortization									1,966	1,904	1,820
Interest expense									1,707	1,665	1,743
Losses (gains) on sales of facilities	(15)	(2)	(4)	2	4	2	3	(6)	(23)	5	(29)
Losses on retirement of debt		2			7		79		4	135	335
Legal claim costs (benefits)									(246)	249	78
Total expenses including equity in earnings of affiliates									36,680	35,721	33,437
Income (loss) before income taxes									4,810	3,957	3,481
Provision (benefit) for income taxes									1,378	1,261	1,108
Net income (loss)	1,085	745	791	811	738	573	665	720	3,432	2,696	2,373
Net income attributable to noncontrolling interests									542	567	498
Net income (loss) attributable to HCA Holdings, Inc.	$ 920	$ 618	$ 658	$ 694	$ 582	$ 449	$ 507	$ 591	2,890	2,129	1,875
Comprehensive income (loss) attributable to HCA Holdings, Inc.									2,817	2,187	1,809
HCA Holdings, Inc. Issuer [Member]
Supplemental Condensed Consolidating Financial Information [Line Items]
Other operating expenses									6	(2)	20
Equity in earnings of affiliates									(2,738)	(2,352)	(2,003)
Interest expense									64	115	184
Losses on retirement of debt										122
Legal claim costs (benefits)										120
Total expenses including equity in earnings of affiliates									(2,668)	(1,997)	(1,799)
Income (loss) before income taxes									2,668	1,997	1,799
Provision (benefit) for income taxes									(222)	(132)	(76)
Net income (loss)									2,890	2,129	1,875
Net income (loss) attributable to HCA Holdings, Inc.									2,890	2,129	1,875
Comprehensive income (loss) attributable to HCA Holdings, Inc.									2,817	2,187	1,809
HCA Inc. Issuer [Member]
Supplemental Condensed Consolidating Financial Information [Line Items]
Interest expense									2,756	2,445	2,175
Losses on retirement of debt									4	13	335
Legal claim costs (benefits)									(246)	129	78
Total expenses including equity in earnings of affiliates									2,514	2,587	2,588
Income (loss) before income taxes									(2,514)	(2,587)	(2,588)
Provision (benefit) for income taxes									(928)	(962)	(961)
Net income (loss)									(1,586)	(1,625)	(1,627)
Net income (loss) attributable to HCA Holdings, Inc.									(1,586)	(1,625)	(1,627)
Comprehensive income (loss) attributable to HCA Holdings, Inc.									(1,505)	(1,568)	(1,566)
Subsidiary Guarantors [Member]
Supplemental Condensed Consolidating Financial Information [Line Items]
Revenues before provision for doubtful accounts									22,906	22,272	20,533
Provision for doubtful accounts									1,885	2,099	1,777
Revenues									21,021	20,173	18,756
Salaries and benefits									9,435	9,131	8,574
Supplies									3,607	3,464	3,280
Other operating expenses									3,474	3,324	3,138
Electronic health record incentive income									(6)	(31)	(85)
Equity in earnings of affiliates									(6)	(6)	(7)
Depreciation and amortization									950	915	888
Interest expense									(891)	(766)	(559)
Losses (gains) on sales of facilities									3	(2)	(25)
Management fees									(763)	(676)	(662)
Total expenses including equity in earnings of affiliates									15,803	15,353	14,542
Income (loss) before income taxes									5,218	4,820	4,214
Provision (benefit) for income taxes									1,891	1,758	1,533
Net income (loss)									3,327	3,062	2,681
Net income attributable to noncontrolling interests									92	92	87
Net income (loss) attributable to HCA Holdings, Inc.									3,235	2,970	2,594
Comprehensive income (loss) attributable to HCA Holdings, Inc.									3,224	3,009	2,508
Subsidiary Non-Guarantors [Member]
Supplemental Condensed Consolidating Financial Information [Line Items]
Revenues before provision for doubtful accounts									21,841	21,319	19,554
Provision for doubtful accounts									1,372	1,814	1,392
Revenues									20,469	19,505	18,162
Salaries and benefits									9,462	8,984	8,067
Supplies									3,326	3,174	2,982
Other operating expenses									4,028	3,781	3,597
Electronic health record incentive income									(6)	(16)	(40)
Equity in earnings of affiliates									(48)	(40)	(36)
Depreciation and amortization									1,016	989	932
Interest expense									(222)	(129)	(57)
Losses (gains) on sales of facilities									(26)	7	(4)
Management fees									763	676	662
Total expenses including equity in earnings of affiliates									18,293	17,426	16,103
Income (loss) before income taxes									2,176	2,079	2,059
Provision (benefit) for income taxes									637	597	612
Net income (loss)									1,539	1,482	1,447
Net income attributable to noncontrolling interests									450	475	411
Net income (loss) attributable to HCA Holdings, Inc.									1,089	1,007	1,036
Comprehensive income (loss) attributable to HCA Holdings, Inc.									946	969	995
Eliminations [Member]
Supplemental Condensed Consolidating Financial Information [Line Items]
Equity in earnings of affiliates									2,738	2,352	2,003
Total expenses including equity in earnings of affiliates									2,738	2,352	2,003
Income (loss) before income taxes									(2,738)	(2,352)	(2,003)
Net income (loss)									(2,738)	(2,352)	(2,003)
Net income (loss) attributable to HCA Holdings, Inc.									(2,738)	(2,352)	(2,003)
Comprehensive income (loss) attributable to HCA Holdings, Inc.									$ (2,665)	$ (2,410)	$ (1,937)