LONG-TERM DEBT AND LEASE OBLIGATIONS - Credit Agreement and Letter of Credit Facility (Details) $ in Millions	12 Months Ended
Dec. 31, 2016 USD ($)
Credit Agreement
LONG-TERM DEBT AND LEASE OBLIGATIONS
Revolving credit facility, maximum borrowing capacity	$ 1,000
Line of credit facility, subfacility maximum available capacity	300
Standby letters of credit outstanding	2
Amount available for borrowing under revolving credit facility	$ 998
Credit Agreement \| Minimum
LONG-TERM DEBT AND LEASE OBLIGATIONS
Unused commitment fee (as a percent)	0.25%
Credit Agreement \| Maximum
LONG-TERM DEBT AND LEASE OBLIGATIONS
Unused commitment fee (as a percent)	0.375%
Credit Agreement \| Base rate \| Minimum
LONG-TERM DEBT AND LEASE OBLIGATIONS
Margin on variable rate (as a percent)	0.25%
Credit Agreement \| Base rate \| Maximum
LONG-TERM DEBT AND LEASE OBLIGATIONS
Margin on variable rate (as a percent)	0.75%
Credit Agreement \| LIBOR \| Minimum
LONG-TERM DEBT AND LEASE OBLIGATIONS
Margin on variable rate (as a percent)	1.25%
Credit Agreement \| LIBOR \| Maximum
LONG-TERM DEBT AND LEASE OBLIGATIONS
Margin on variable rate (as a percent)	1.75%
Letter of Credit Facility
LONG-TERM DEBT AND LEASE OBLIGATIONS
Revolving credit facility, maximum borrowing capacity	$ 180
Standby letters of credit outstanding	108
Borrowing capacity after increase subject to certain conditions	$ 200
Unused commitment fee after step down	0.50%
Secured debt to EBITDA ratio	3.00
Issuance fee (percentage)	1.50%
Issuance fee, based on face amount (percentage)	0.125%
Senior Notes
LONG-TERM DEBT AND LEASE OBLIGATIONS
Borrowings outstanding	$ 750
Debt Instrument, Redemption Price, Percentage	100.00%
Senior Secured Notes
LONG-TERM DEBT AND LEASE OBLIGATIONS
Debt Instrument, Redemption Price, Percentage	100.00%
Debt Instrument, Repurchase Obligation Due to Change of Control Percentage of Principal	101.00%

Represents the ratio for secured debt to EBITDA required to be maintained under financial covenants.

No definition available.

Name:	thc_DebtInstrumentCovenantSecuredDebtToEbitdaRatio
Namespace Prefix:	thc_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the issuance fee, expressed as a percentage.

+ References

No definition available.

+ Details

Name:	thc_DebtInstrumentIssuanceFee
Namespace Prefix:	thc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the issuance fee, expressed as a percentage of the face amount.

+ References

No definition available.

+ Details

Name:	thc_DebtInstrumentIssuanceFeeBasedOnFaceAmount
Namespace Prefix:	thc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of the principal amount at which the entity is obligated to offer to repurchase the debt instrument due to a change in control.

+ References

No definition available.

+ Details

Name:	thc_DebtInstrumentRepurchaseObligationDueToChangeOfControlPercentageOfPrincipal
Namespace Prefix:	thc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility after an increase subject to certain conditions, without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

No definition available.

+ Details

Name:	thc_LineOfCreditFacilityMaximumBorrowingCapacityAfterIncreaseSubjectToCertainConditions
Namespace Prefix:	thc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the maximum available capacity under the subfacility for standby letters of credit.

+ References

No definition available.

+ Details

Name:	thc_LineOfCreditFacilitySubfacilityForStandbyLettersOfCreditMaximumAvailableCapacity
Namespace Prefix:	thc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the unused commitment fee after step down, expressed as a percentage.

+ References

No definition available.

+ Details

Name:	thc_LineOfCreditFacilityUnusedCapacityCommitmentFeeAfterStepDownPercentage
Namespace Prefix:	thc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

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- Details

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- Details

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- Details

Name:	us-gaap_VariableRateAxis=us-gaap_BaseRateMember
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- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
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- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
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- Details

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