Consolidated Income Statements - USD ($) shares in Thousands, $ 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
Income Statement [Abstract]
Revenues before the 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 before income taxes									4,810	3,957	3,481
Provision for income taxes									1,378	1,261	1,108
Net income	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 attributable to HCA Holdings, Inc.	$ 920	$ 618	$ 658	$ 694	$ 582	$ 449	$ 507	$ 591	$ 2,890	$ 2,129	$ 1,875
Per share data:
Basic earnings per share	$ 2.46	$ 1.63	$ 1.70	$ 1.75	$ 1.44	$ 1.08	$ 1.22	$ 1.41	$ 7.53	$ 5.14	$ 4.30
Diluted earnings per share	$ 2.39	$ 1.59	$ 1.65	$ 1.69	$ 1.40	$ 1.05	$ 1.18	$ 1.36	$ 7.30	$ 4.99	$ 4.16
Shares used in earnings per share calculations (in millions):
Basic									383,591	414,193	435,668
Diluted									395,851	426,721	450,352