Appendix 1 Group Companies - Schedule of Percentage of Control in Each Subsidiary (Detail)		12 Months Ended
Oct. 01, 2019	Dec. 31, 2019	Dec. 31, 2018
Empresa Electrica Pehuenche S.A. [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Taxpayer ID No. (RUT)		96.504.980-0
Company		Empresa Eléctrica Pehuenche S.A.
Functional Currency		Chilean peso
Percentage of direct control		92.65%	92.65%
Percentage of indirect control		0.00%	0.00%
Percentage of control		92.65%	92.65%
Relationship		Subsidiary
Country		Chile
Activity		Complete electric energy cycle
GasAtacama Chile S.A. [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Taxpayer ID No. (RUT)		96.830.980-3
Company		GasAtacama Chile S.A.
Functional Currency		Chilean peso
Percentage of direct control		0.00%	97.37%
Percentage of indirect control		0.00%	0.00%
Percentage of control		0.00%	97.37%
Relationship		Subsidiary
Country		Chile
Activity		Management of Companies
Percentage of shares acquired	2.63%
Gasoducto Atacama Argentina S.A. [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Taxpayer ID No. (RUT)		78.952.420-3
Company		Gasoducto Atacama Argentina S.A.
Functional Currency		Chilean peso
Percentage of direct control		0.00%	0.03%
Percentage of indirect control		0.00%	99.97%
Percentage of control		0.00%	100.00%
Relationship		Subsidiary
Country		Chile
Activity		Natural gas exploitation and transportation
Enel Generacion Chile S.A [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of control	100.00%

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Proportion of indirect ownership interest in a subsidiary.

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The country in which a subsidiary of the entity is incorporated. [Refer: Subsidiaries [member]]

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The description of the nature of the related party relationships. [Refer: Related parties [member]]

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The name of a subsidiary. [Refer: Subsidiaries [member]]

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The percentage of voting equity interests acquired in a business combination. [Refer: Business combinations [member]]

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The proportion of ownership interest in a subsidiary attributable to the entity. [Refer: Subsidiaries [member]]

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