CASH AND CASH EQUIVALENTS AND INVESTMENTS. ADDITIONAL INFORMATION ON THE CONSOLIDATED STATEMENTS OF CASH FLOWS - Movements in the allowance of credit risk (Details) $ in Millions	12 Months Ended
Dec. 31, 2019 ARS ($)
Movements in the allowance of current credit risk
Additions - Other financial results, net	$ (1,140)
Uses (includes RECPAM)	1,077
At the end of the year	(63)
Movements in the allowance of non-current credit risk
Additions - Other financial results, net	(1,429)
Uses (includes RECPAM)	450
At the end of the year	$ (979)

The amount of current additional allowance for credit losses of financial assets recognised in profit or loss.

No definition available.

Name:	teo_AdditionalAllowanceRecognisedInProfitOrLossAllowanceAccountForCurrentCreditLossesOfFinancialAssets
Namespace Prefix:	teo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The amount of non-current additional allowance for credit losses of financial assets recognised in profit or loss.

No definition available.

Name:	teo_AdditionalAllowanceRecognisedInProfitOrLossAllowanceAccountForNonCurrentCreditLossesOfFinancialAssets
Namespace Prefix:	teo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The amount of an allowance account used to record impairments to financial assets due to credit losses, classified as current.

No definition available.

Name:	teo_AllowanceAccountForCreditLossesOfFinancialAssetsCurrent
Namespace Prefix:	teo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The amount of an allowance account used to record impairments to financial assets due to credit losses, classified as non-current.

No definition available.

Name:	teo_AllowanceAccountForCreditLossesOfFinancialAssetsNonCurrent
Namespace Prefix:	teo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

No definition available.

Name:	teo_MovementInAllowanceAccountForCreditLossesOfFinancialAssetsCurrentAbstract
Namespace Prefix:	teo_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

No definition available.

Name:	teo_MovementInAllowanceAccountForCreditLossesOfFinancialAssetsNonCurrentAbstract
Namespace Prefix:	teo_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The decrease in an current allowance account for credit losses of financial assets resulting from the utilisation of the allowance.

No definition available.

Name:	teo_UtilisationCurrentAllowanceAccountForCreditLossesOfFinancialAssets
Namespace Prefix:	teo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The decrease in an non-current allowance account for credit losses of financial assets resulting from the utilisation of the allowance.

No definition available.

Name:	teo_UtilisationNonCurrentAllowanceAccountForCreditLossesOfFinancialAssets
Namespace Prefix:	teo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration