Condensed Consolidated Income Statements (Unaudited) - USD ($) shares in Thousands, $ in Millions		3 Months Ended				9 Months Ended
	Dec. 09, 2015	Sep. 30, 2016	Sep. 30, 2015	Mar. 31, 2014	Dec. 31, 2012	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Revenues before provision for doubtful accounts		$ 11,110	$ 11,014			$ 33,241	$ 32,268
Provision for doubtful accounts		840	1,158			2,392	2,839
Revenues		10,270	9,856			30,849	29,429
Salaries and benefits		4,740	4,619			14,133	13,509
Supplies		1,699	1,644			5,131	4,952
Other operating expenses		1,897	1,796			5,627	5,268
Electronic health record incentive income		(1)	(9)			(10)	(46)
Equity in earnings of affiliates		(22)	(9)			(44)	(38)
Depreciation and amortization		495	482			1,463	1,424
Interest expense		432	411			1,275	1,255
Losses (gains) on sales of facilities		(3)	2			(8)	(2)
Losses on retirement of debt		4				4	125
Legal claim costs	$ 434	11	77	$ 78	$ 175	33	77
Total expenses including equity in earnings of affiliates		9,252	9,013			27,604	26,524
Income before income taxes		1,018	843			3,245	2,905
Provision for income taxes		273	270			898	947
Net income		745	573			2,347	1,958
Net income attributable to noncontrolling interests		127	124			377	411
Net income attributable to HCA Holdings, Inc.		$ 618	$ 449			$ 1,970	$ 1,547
Per share data:
Basic earnings per share		$ 1.63	$ 1.08			$ 5.09	$ 3.71
Diluted earnings per share		$ 1.59	$ 1.05			$ 4.93	$ 3.60
Shares used in earnings per share calculations (in millions):
Basic		378,199	414,939			386,968	417,146
Diluted		389,592	426,441			399,577	430,354