Name:	tcp_LengthOfPipelineOwned
Namespace Prefix:	tcp_
Data Type:	num:lengthItemType
Balance Type:	na
Period Type:	duration

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

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.

No definition available.

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

The number of units or percentage investment held in the subsidiary by the limited liability company or limited partnership.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 320
-Section S99
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=50485924&loc=d3e611443-123010

Name:	us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipOwnershipInterest
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Name:	srt_OwnershipAxis=tcp_GasTransmissionNorthwestLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_OwnershipAxis=tcp_BisonPipelineLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_OwnershipAxis=tcp_NorthBajaPipelineLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_OwnershipAxis=tcp_TuscaroraGasTransmissionCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_OwnershipAxis=tcp_NorthernBorderPipelineCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_OwnershipAxis=tcp_PortlandNaturalGasTransmissionSystemMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_CounterpartyNameAxis=tcp_MaritimesAndNortheastPipelineLlcMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=tcp_PortlandNaturalGasTransmissionSystemMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_OwnershipAxis=tcp_NorthNewEnglandInvestmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_OwnershipAxis=tcp_GreatLakesGasTransmissionLimitedPartnershipMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_CounterpartyNameAxis=tcp_TransCanadaCorporationAndSubsidiariesExcludingGeneralPartnerSubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_OwnershipAxis=tcp_IroquoisGasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	dei_LegalEntityAxis=tcp_TransCanadaCorporationAndSubsidiariesExcludingGeneralPartnerSubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: