Represents the number of financial institutions (Managers) acting as sales agents.

No definition available.

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- Definition

Represents the number of sales agents (Managers) required to be in agreement with the entity for a sale of equity other than by means of ordinary brokers' transactions on a stock exchange at market prices or in block transactions.

+ References

No definition available.

+ Details

Name:	tclp_OtherEquitySalesMethodNumberOfManagersInAgreement
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Data Type:	xbrli:integerItemType
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Period Type:	duration

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 272

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Total contributions made by each class of partners (i.e., general, limited and preferred partners).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Monetary value of the issuance of new units of limited partnership interest in a public offering.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Monetary value of the issuance of new units of limited partnership interest in a public offering, net of offering costs. This is a parenthetical disclosure.

+ References

+ Details

Name:	us-gaap_PartnersCapitalAccountPublicSaleOfUnitsNetOfOfferingCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The number of units sold in a public offering of each class of partners' capital account. Units represent shares of ownership of the general, limited, and preferred partners.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 5

-Subparagraph (SAB TOPIC 4.F)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 16

-Subparagraph a, b

-Article 6

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash outflow for cost incurred directly with the issuance of an equity security.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 15

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3291-108585

+ Details

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

- Details

Name:	us-gaap_ScheduleOfCapitalizationEquityLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	dei_LegalEntityAxis=tclp_TCPipeLinesGeneralPartnershipIncorporatedMember
Namespace Prefix:
Data Type:	na
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Period Type:

- Details

Name:	tclp_SaleOfLimitedPartnershipUnitsAxis=tclp_AtMarketEquityIssuanceProgramMember
Namespace Prefix:
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PARTNERS' EQUITY (Details) (USD $)	3 Months Ended		1 Months Ended	8 Months Ended
PARTNERS' EQUITY (Details) (USD $)	Mar. 31, 2015	Mar. 31, 2014	Aug. 31, 2014 Institution	Mar. 31, 2015
TC PipeLines GP, Inc. \| General Partner
Partners' Equity
Ownership interest in the Partnership (as a percent)	2.00%	2.00%
ATM Equity Issuance Program \| Common Units (Limited Partners)
Partners' Equity
Number of financial institutions			5
Units sold	54,701			1,288,481
Net proceeds from public offering of common units	3,400,000
Sales agent commissions	34,000
ATM Equity Issuance Program \| TC PipeLines GP, Inc. \| General Partner
Partners' Equity
Equity contribution	100,000
ATM Equity Issuance Program \| Maximum \| Expected \| Common Units (Limited Partners)
Partners' Equity
Gross proceeds from sale of common units			200,000,000
ATM Equity Issuance Program \| Minimum \| Common Units (Limited Partners)
Partners' Equity
Number of managers to agree with equity sale method			1