SIGNIFICANT ACCOUNTING POLICIES - Segment Reporting (Details)	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Revenue generated by general hospitals	80.00%	81.00%	81.00%

Represents the percentage of net operating revenues generated by the entity's general hospitals

No definition available.

Name:	thc_PercentageOfNetOperatingRevenuesGeneratedByGeneralHospitals
Namespace Prefix:	thc_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant