Name:	tcp_CapitalUnitsPercentageOfSubsidiaryDistributionsSubjectToRightsOfHolderToReceivePartnersCapitalAccountDistributionsAtSpecifiedPercentageInExcessOfSpecifiedAmount
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Data Type:	num:percentItemType
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Represents, for rights of the holder of capital units to receive partners capital account distributions, the initial percentage (100%) to be applied during a specified period to 30 percent of subsidiary distributions in excess of a specified amount, as defined.

No definition available.

Name:	tcp_CapitalUnitsRightsOfHolderToReceivePartnersCapitalAccountDistributionsInitialEffectivePercentageAppliedToSubsidiaryDistributionsInExcessOfSpecifiedAmount
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Represents the amount of reduction of the rights of the holder of capital units to receive partner's capital account distributions.

No definition available.

Name:	tcp_CapitalUnitsRightsOfHolderToReceivePartnersCapitalAccountDistributionsReductionOfSubsidiaryDistributions
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Represents, for rights of the holder of capital units to receive partners capital account distributions, the threshold of subsidiary distributions for payment to the holder, prorated in the year of issuance.

No definition available.

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Amount after tax of income (loss) of subsidiary attributable to the former parent of an entity acquired in a transaction between entities under common control.

No definition available.

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Aggregate amount of net income allocated to general partners and limited partners, excluding any net income (loss) attributable to the former parent of an entity acquired in a transaction between entities under common control.

No definition available.

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Aggregate amount of net income allocated to general partners, net of general partner incentive distributions, and net income allocated to limited partner common units.

No definition available.

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- References

No definition available.

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No definition available.

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Amount, before tax, of income (loss) attributable to parent. Includes, but is not limited to, income (loss) from continuing operations, discontinued operations and equity method investments.

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Percentage investment held by the managing member or general partner of the limited liability company (LLC) or limited partnership (LP).

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Amount of cash or stock or unit payment to a limited liability corporation managing member or limited partnership general partner after the end of the accounting period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Aggregate amount of net income allocated to general partners.

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Aggregate amount of net income allocated to limited partners.

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The amount of net income or loss for the period per each limited partnership and general partnership unit in instances when basic and diluted earnings per unit are the same amount and aggregated on the face of the financial statements. Basic earnings per unit is the amount of net income or loss for the period per unit outstanding during the reporting period. Diluted earnings per unit includes the amount of net income or loss for the period available to each limited and general partnership unit outstanding during the reporting period and to each unit that would have been outstanding assuming the issuance of units for all dilutive potential units outstanding during the reporting period.

No definition available.

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Data Type:	num:perShareItemType
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The average number of limited partnership and general partnership units issued and outstanding that are used in calculating basic and diluted earnings per limited partnership and general partnership unit.

No definition available.

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Data Type:	xbrli:sharesItemType
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Name:	us-gaap_LimitedPartnersCapitalAccountByClassAxis=tcp_LimitedPartnerCommonUnitMember
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Name:	dei_LegalEntityAxis=tcp_TCPipelinesGPInc.Member
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Name:	srt_OwnershipAxis=tcp_TCPipelinesLpMember
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Name:	dei_LegalEntityAxis=tcp_GasTransmissionNorthwestLLCMember
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