Supplemental Condensed Consolidating Financial Information and Other Collateral-Related Information - Schedule of Condensed Consolidating Balance Sheet (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 502	$ 732
Accounts receivable, net	6,789	6,501
Inventories	1,732	1,573
Other	1,190	1,171
Total current assets	10,213	9,977
Property and equipment, net	19,757	17,895
Investments of insurance subsidiaries	362	418
Investments in and advances to affiliates	232	199
Goodwill and other intangible assets	7,953	7,394	$ 6,704	$ 6,731
Other	690	710
Total assets	39,207	36,593	33,758
Current liabilities:
Accounts payable	2,577	2,606
Accrued salaries	1,580	1,369
Other accrued expenses	2,624	1,983
Long-term debt due within one year	788	200
Total current liabilities	7,569	6,158
Long-term debt, net	32,033	32,858
Professional liability risks	1,275	1,198
Income taxes and other liabilities	1,248	1,374
Total liabilities	42,125	41,588
Stockholders' (deficit) equity attributable to HCA Healthcare, Inc.	(4,950)	(6,806)
Noncontrolling interests	2,032	1,811
Total stockholders' deficit	(2,918)	(4,995)	$ (5,633)	$ (6,046)
Total liabilities and stockholders' deficit	39,207	36,593
HCA Healthcare, Inc. Issuer [Member]
Current assets:
Cash and cash equivalents		1
Total current assets		1
Investments in and advances to affiliates	33,166	29,581
Other	478	510
Total assets	33,644	30,092
Current liabilities:
Other accrued expenses	142	29
Total current liabilities	142	29
Long-term debt, net	996	995
Intercompany balances	36,951	35,322
Income taxes and other liabilities	505	552
Total liabilities	38,594	36,898
Stockholders' (deficit) equity attributable to HCA Healthcare, Inc.	(4,950)	(6,806)
Total stockholders' deficit	(4,950)	(6,806)
Total liabilities and stockholders' deficit	33,644	30,092
HCA Inc. Issuer [Member]
Current assets:
Other	64	50
Total assets	64	50
Current liabilities:
Other accrued expenses	403	378
Long-term debt due within one year	696	97
Total current liabilities	1,099	475
Long-term debt, net	30,544	31,367
Intercompany balances	(6,789)	(9,742)
Total liabilities	24,854	22,100
Stockholders' (deficit) equity attributable to HCA Healthcare, Inc.	(24,790)	(22,050)
Total stockholders' deficit	(24,790)	(22,050)
Total liabilities and stockholders' deficit	64	50
Subsidiary Guarantors [Member]
Current assets:
Cash and cash equivalents	174	112
Accounts receivable, net	3,964	3,693
Inventories	1,178	1,030
Other	669	663
Total current assets	5,985	5,498
Property and equipment, net	12,450	11,110
Investments in and advances to affiliates	29	22
Goodwill and other intangible assets	5,724	4,893
Other	35	47
Total assets	24,223	21,570
Current liabilities:
Accounts payable	1,721	1,793
Accrued salaries	998	862
Other accrued expenses	905	536
Long-term debt due within one year	55	64
Total current liabilities	3,679	3,255
Long-term debt, net	212	307
Intercompany balances	(28,415)	(25,228)
Income taxes and other liabilities	223	357
Total liabilities	(24,301)	(21,309)
Stockholders' (deficit) equity attributable to HCA Healthcare, Inc.	48,437	42,755
Noncontrolling interests	87	124
Total stockholders' deficit	48,524	42,879
Total liabilities and stockholders' deficit	24,223	21,570
Subsidiary Non-Guarantors [Member]
Current assets:
Cash and cash equivalents	328	619
Accounts receivable, net	2,825	2,808
Inventories	554	543
Other	521	508
Total current assets	4,228	4,478
Property and equipment, net	7,307	6,785
Investments of insurance subsidiaries	362	418
Investments in and advances to affiliates	203	177
Goodwill and other intangible assets	2,229	2,501
Other	113	103
Total assets	14,442	14,462
Current liabilities:
Accounts payable	856	813
Accrued salaries	582	507
Other accrued expenses	1,174	1,040
Long-term debt due within one year	37	39
Total current liabilities	2,649	2,399
Long-term debt, net	281	189
Intercompany balances	(1,747)	(352)
Professional liability risks	1,275	1,198
Income taxes and other liabilities	520	465
Total liabilities	2,978	3,899
Stockholders' (deficit) equity attributable to HCA Healthcare, Inc.	9,519	8,876
Noncontrolling interests	1,945	1,687
Total stockholders' deficit	11,464	10,563
Total liabilities and stockholders' deficit	14,442	14,462
Eliminations [Member]
Current assets:
Investments in and advances to affiliates	(33,166)	(29,581)
Total assets	(33,166)	(29,581)
Current liabilities:
Stockholders' (deficit) equity attributable to HCA Healthcare, Inc.	(33,166)	(29,581)
Total stockholders' deficit	(33,166)	(29,581)
Total liabilities and stockholders' deficit	$ (33,166)	$ (29,581)