Condensed Consolidated Income Statements (Unaudited) - USD ($) shares in Thousands, $ in Millions		3 Months Ended
	Dec. 09, 2015	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2012
Income Statement [Abstract]
Revenues before provision for doubtful accounts		$ 11,050		$ 10,322
Provision for doubtful accounts		790		646
Revenues		10,260		9,676
Salaries and benefits		4,702		4,398
Supplies		1,714		1,638
Other operating expenses		1,857		1,717
Electronic health record incentive income		(4)		(19)
Equity in earnings of affiliates		(12)		(19)
Depreciation and amortization		479		473
Interest expense		416		419
Losses (gains) on sales of facilities		1		(9)
Legal claim costs	$ 434	12	$ 120		$ 78	$ 175
Total expenses including equity in earnings of affiliates		9,165		8,598
Income before income taxes		1,095		1,078
Provision for income taxes		284		358
Net income		811		720
Net income attributable to noncontrolling interests		117		129
Net income attributable to HCA Holdings, Inc.		$ 694		$ 591
Per share data:
Basic earnings per share		$ 1.75		$ 1.41
Diluted earnings per share		$ 1.69		$ 1.36
Shares used in earnings per share calculations (in millions):
Basic		396,397		420,148
Diluted		410,575		435,309