Supplemental Condensed Consolidating Financial Information and Other Collateral-Related Information - Schedule of Condensed Consolidating Balance Sheet (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 621	$ 502
Accounts receivable	7,380	6,789
Inventories	1,849	1,732
Other	1,346	1,190
Total current assets	11,196	10,213
Property and equipment, net	22,715	19,757
Investments of insurance subsidiaries	315	362
Investments in and advances to affiliates	249	232
Goodwill and other intangible assets	8,269	7,953	$ 7,394	$ 6,704
Right-of-use operating lease assets	1,834
Other	480	690
Total assets	45,058	39,207	36,593
Current liabilities:
Accounts payable	2,905	2,577
Accrued salaries	1,775	1,580
Other accrued expenses	2,932	2,624
Long-term debt due within one year	145	788
Total current liabilities	7,757	7,569
Long-term debt, net	33,577	32,033
Professional liability risks	1,370	1,275
Right-of-use operating lease obligations	1,499
Income taxes and other liabilities	1,420	1,248
Total liabilities	45,623	42,125
Stockholders' (deficit) equity attributable to HCA Healthcare, Inc.	(2,808)	(4,950)
Noncontrolling interests	2,243	2,032
Total stockholders' deficit	(565)	(2,918)	$ (4,995)	$ (5,633)
Total liabilities and stockholders' deficit	45,058	39,207
HCA Healthcare, Inc. Issuer [Member]
Current assets:
Investments in and advances to affiliates	36,684	33,166
Other	300	478
Total assets	36,984	33,644
Current liabilities:
Other accrued expenses	85	142
Total current liabilities	85	142
Long-term debt, net	998	996
Intercompany balances	38,089	36,951
Income taxes and other liabilities	620	505
Total liabilities	39,792	38,594
Stockholders' (deficit) equity attributable to HCA Healthcare, Inc.	(2,808)	(4,950)
Total stockholders' deficit	(2,808)	(4,950)
Total liabilities and stockholders' deficit	36,984	33,644
HCA Inc. Issuer [Member]
Current assets:
Other	3	64
Total assets	3	64
Current liabilities:
Other accrued expenses	341	403
Long-term debt due within one year	54	696
Total current liabilities	395	1,099
Long-term debt, net	32,016	30,544
Intercompany balances	(4,314)	(6,789)
Income taxes and other liabilities	7
Total liabilities	28,104	24,854
Stockholders' (deficit) equity attributable to HCA Healthcare, Inc.	(28,101)	(24,790)
Total stockholders' deficit	(28,101)	(24,790)
Total liabilities and stockholders' deficit	3	64
Subsidiary Guarantors [Member]
Current assets:
Cash and cash equivalents	118	174
Accounts receivable	4,037	3,964
Inventories	1,208	1,178
Other	727	669
Total current assets	6,090	5,985
Property and equipment, net	13,418	12,450
Investments in and advances to affiliates	29	29
Goodwill and other intangible assets	5,743	5,724
Right-of-use operating lease assets	455
Other	29	35
Total assets	25,764	24,223
Current liabilities:
Accounts payable	1,903	1,721
Accrued salaries	1,070	998
Other accrued expenses	1,001	905
Long-term debt due within one year	50	55
Total current liabilities	4,024	3,679
Long-term debt, net	213	212
Intercompany balances	(33,828)	(28,415)
Right-of-use operating lease obligations	345
Income taxes and other liabilities	252	223
Total liabilities	(28,994)	(24,301)
Stockholders' (deficit) equity attributable to HCA Healthcare, Inc.	54,652	48,437
Noncontrolling interests	106	87
Total stockholders' deficit	54,758	48,524
Total liabilities and stockholders' deficit	25,764	24,223
Subsidiary Non-Guarantors [Member]
Current assets:
Cash and cash equivalents	503	328
Accounts receivable	3,343	2,825
Inventories	641	554
Other	619	521
Total current assets	5,106	4,228
Property and equipment, net	9,297	7,307
Investments of insurance subsidiaries	315	362
Investments in and advances to affiliates	220	203
Goodwill and other intangible assets	2,526	2,229
Right-of-use operating lease assets	1,379
Other	148	113
Total assets	18,991	14,442
Current liabilities:
Accounts payable	1,002	856
Accrued salaries	705	582
Other accrued expenses	1,505	1,174
Long-term debt due within one year	41	37
Total current liabilities	3,253	2,649
Long-term debt, net	350	281
Intercompany balances	53	(1,747)
Professional liability risks	1,370	1,275
Right-of-use operating lease obligations	1,154
Income taxes and other liabilities	541	520
Total liabilities	6,721	2,978
Stockholders' (deficit) equity attributable to HCA Healthcare, Inc.	10,133	9,519
Noncontrolling interests	2,137	1,945
Total stockholders' deficit	12,270	11,464
Total liabilities and stockholders' deficit	18,991	14,442
Eliminations [Member]
Current assets:
Investments in and advances to affiliates	(36,684)	(33,166)
Total assets	(36,684)	(33,166)
Current liabilities:
Stockholders' (deficit) equity attributable to HCA Healthcare, Inc.	(36,684)	(33,166)
Total stockholders' deficit	(36,684)	(33,166)
Total liabilities and stockholders' deficit	$ (36,684)	$ (33,166)