Share Repurchase Transactions and Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss (Parenthetical) (Detail) $ in Millions	6 Months Ended
Jun. 30, 2026 USD ($)
Equity [Abstract]
Foreign currency translation adjustments, net of income tax benefits	$ 3

Other comprehensive loss foreign currency translation adjustment tax benefit.

No definition available.

Name:	hca_OtherComprehensiveLossForeignCurrencyTranslationAdjustmentTaxBenefit
Namespace Prefix:	hca_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration