DESCRIPTION OF TC ENERGY'S BUSINESS (Details)	12 Months Ended
Dec. 31, 2019 plant segment mi km Bcf
Segment Reporting Information [Line Items]
Number of business segments in which the entity operates \| segment	5
Canadian Natural Gas Pipelines
Segment Reporting Information [Line Items]
Investments of regulated natural gas pipelines (in kilometers) \| km	40,658
Investments of regulated natural gas pipelines (in miles) \| mi	25,264
U.S. Natural Gas Pipelines
Segment Reporting Information [Line Items]
Investments of regulated natural gas pipelines (in kilometers) \| km	50,089
Investments of regulated natural gas pipelines (in miles) \| mi	31,124
Investments of regulated natural gas storage facilities (in billion cubic feet) \| Bcf	535
Mexico Natural Gas Pipelines
Segment Reporting Information [Line Items]
Investments of regulated natural gas pipelines (in kilometers) \| km	2,503
Investments of regulated natural gas pipelines (in miles) \| mi	1,554
Liquids Pipelines
Segment Reporting Information [Line Items]
Wholly owned and operated crude oil pipeline systems (in kilometers) \| km	4,946
Wholly owned and operated crude oil pipeline systems (in miles) \| mi	3,075
Power and Storage
Segment Reporting Information [Line Items]
Number of electrical power generation plants \| plant	10
Non-regulated natural gas storage facilities (in billion cubic feet) \| Bcf	118

Public Utilities, Property, Plant and Equipment, Liquids Pipelines, in Kilometers

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Public Utilities, Property, Plant and Equipment, Liquids Pipelines, in Miles

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Public Utilities, Property, Plant and Equipment, Non-Regulated Natural Gas Storage Facilities, in Billion Cubic Feet

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Public Utilities, Property, Plant and Equipment, Number of Electrical Power Generation Plants

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Public Utilities, Property, Plant and Equipment, Regulated Natural Gas Pipelines, in Kilometers

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Public Utilities, Property, Plant and Equipment, Regulated Natural Gas Pipelines, in Miles

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Public Utilities, Property, Plant and Equipment, Regulated Natural Gas Storage Facilities, in Billion Cubic Feet

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- Definition

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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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.

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