Supplemental Condensed Consolidating Financial Information and Other Collateral-Related Information - Schedule of Consolidated Statements of Stockholder's Deficit (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based benefit plans	$ 281	$ 233	$ 523
Other	10	(6)	18
Healthtrust, Inc. [Member]
Share-based benefit plans	281	233	523
Other	(10)	(2)	(18)
Distributions from HCA Holdings, Inc., net of contributions to HCA Holdings, Inc.	$ 271	$ 231	$ 505

This element represents movements included in the statement of changes in stockholders' equity which are not separately disclosed or provided for elsewhere in the taxonomy.

No definition available.

Name:	us-gaap_StockholdersEquityOther
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration