Appendix 3 Associates and Joint Ventures - Summary of Investments Accounted for Using the Equity Method (Detail)	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Centrales Hidroelectricas de Aysen S.A. [Member]
Disclosure Of Significant Investments In Associates And Joint Ventures [Line Items]
Activity	Hydroelectric plant development and operation
Taxpayer ID No.	76.652.400-1
Company	Centrales Hidroelectricas De Aysen S.A.	Centrales Hidroelectricas De Aysen S.A.
Currency	Chilean peso	Chilean peso
Percentage of direct ownership interest	51.00%	51.00%
Percentage of indirect ownership interest	0.00%	0.00%
Total	51.00%	51.00%
Relationship	Joint venture
Country	Chile
Transmisora Electrica De Quillota Ltda [Member]
Disclosure Of Significant Investments In Associates And Joint Ventures [Line Items]
Activity	Electric energy transportation and distribution
Company	Transmisora Electrica de Quillota Ltda.	Transmisora Electrica de Quillota Ltda.
Currency	Chilean peso	Chilean peso
Electrogas S.A. [Member]
Disclosure Of Significant Investments In Associates And Joint Ventures [Line Items]
Activity	Portfolio company
Taxpayer ID No.	96.806.130-5
Company	Electrogas S.A.	Electrogas S.A.
Currency	U.S. dollar	U.S. dollar
Percentage of direct ownership interest	0.00%	42.50%
Percentage of indirect ownership interest	0.00%	0.00%
Total	0.00%	42.50%
Relationship	Associate
Country	Chile
GNL Chile S.A. [Member]
Disclosure Of Significant Investments In Associates And Joint Ventures [Line Items]
Activity	Promotion of liquefied natural gas supply project
Taxpayer ID No.	76.418.940-K
Company	GNL Chile. S.A.	GNL Chile. S.A.
Currency	U.S. dollar	U.S. dollar
Percentage of direct ownership interest	33.33%	33.33%
Percentage of indirect ownership interest	0.00%	0.00%
Total	33.33%	33.33%
Relationship	Associate
Country	Chile
GNL Quintero S.A. [Member]
Disclosure Of Significant Investments In Associates And Joint Ventures [Line Items]
Activity	Development, design and supply of liquid natural gas degasifying terminal
Taxpayer ID No.	76.788.080-4
Company	GNL Quintero S.A.	GNL Quinteros S.A.
Currency	U.S. dollar	U.S. dollar
Percentage of direct ownership interest	0.00%	0.00%
Percentage of indirect ownership interest	0.00%	0.00%
Total	0.00%	0.00%
Relationship	Associate
Country	Chile
Southern Cone Power Argentina S.A. [Member]
Disclosure Of Significant Investments In Associates And Joint Ventures [Line Items]
Activity	Portfolio company
Taxpayer ID No.	Foreign
Company	Southern Cone Power Argentina S.A.	Southern Cone Power Argentina S.A.
Currency	Argentine peso	Argentine peso
Percentage of direct ownership interest	0.00%	2.00%
Percentage of indirect ownership interest	0.00%	0.00%
Total	0.00%	2.00%
Relationship	Associate
Country	Argentina
Enel Argentina S.A. [Member]
Disclosure Of Significant Investments In Associates And Joint Ventures [Line Items]
Activity	Portfolio company
Taxpayer ID No.	Foreign
Company	Enel Argentina S.A. (ex - Endesa Argentina S.A.)	Enel Argentina S.A. (ex - Endesa Argentina S.A.)
Currency	Argentine peso	Argentine peso
Percentage of direct ownership interest	0.00%	0.00%
Percentage of indirect ownership interest	0.12%	0.12%
Total	0.12%	0.12%
Relationship	Associate
Country	Argentina
Transmisora Electrica de Quillota Ltda. [Member]
Disclosure Of Significant Investments In Associates And Joint Ventures [Line Items]
Taxpayer ID No.	77.017.930-0
Company	Transmisora Electrica de Quillota Ltda.
Currency	U.S. dollar
Percentage of direct ownership interest	0.00%	0.00%
Percentage of indirect ownership interest	50.00%	50.00%
Total	50.00%	50.00%
Relationship	Joint venture
Country	Chile

Country of incorporation or residence of associate and joint ventures.

No definition available.

Name:	eocc_CountryOfIncorporationOrResidenceOfAssociateAndJointVentures
Namespace Prefix:	eocc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Disclosure of significant investments in associates and joint ventures[line items]

+ References

No definition available.

+ Details

Name:	eocc_DisclosureOfSignificantInvestmentsInAssociatesAndJointVenturesLineItems
Namespace Prefix:	eocc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Name of associates and joint ventures.

+ References

No definition available.

+ Details

Name:	eocc_NameOfAssociatesAndJointVentures
Namespace Prefix:	eocc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Proportion of direct ownership interest in associates and joint ventures.

+ References

No definition available.

+ Details

Name:	eocc_ProportionOfDirectOwnershipInterestInAssociatesAndJointVentures
Namespace Prefix:	eocc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Proportion of indirect ownership interest in associates and joint ventures

+ References

No definition available.

+ Details

Name:	eocc_ProportionOfIndirectOwnershipInterestInAssociatesAndJointVentures
Namespace Prefix:	eocc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Proportion of ownership interest in associates and joint ventures.

+ References

No definition available.

+ Details

Name:	eocc_ProportionOfOwnershipInterestInAssociatesAndJointVentures
Namespace Prefix:	eocc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Taxpayer identification number.

+ References

No definition available.

+ Details

Name:	eocc_TaxpayerIdentificationNumber
Namespace Prefix:	eocc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The description of the currency of the primary economic environment in which the entity operates.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 21
-IssueDate 2016-01-13
-Paragraph 53
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=21&date=2016-03-30&anchor=para_53&doctype=Standard
-URIDate 2016-03-31

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 21
-IssueDate 2016-01-13
-Paragraph 57
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=21&date=2016-03-30&anchor=para_57_c&doctype=Standard
-URIDate 2016-03-31

+ Details

Name:	ifrs-full_DescriptionOfFunctionalCurrency
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The description of the nature of the entity's relationship with an associate (for example, describing the nature of the activities of the associate and whether they are strategic to the entity's activities). [Refer: Associates [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2016-01-13
-Paragraph 21
-Subparagraph a
-Clause ii
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=12&date=2016-03-30&anchor=para_21_a_ii&doctype=Standard
-URIDate 2016-03-31

+ Details

Name:	ifrs-full_DescriptionOfNatureOfEntitysRelationshipWithAssociate
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The description of the nature of the entity's relationship with a joint venture (for example, describing the nature of the activities of the joint venture and whether they are strategic to the entity's activities). [Refer: Joint ventures [member]]

+ References

+ Details

Name:	ifrs-full_DescriptionOfNatureOfEntitysRelationshipWithJointVenture
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 24
-IssueDate 2016-01-13
-Paragraph 18
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=24&date=2016-03-30&anchor=para_18&doctype=Standard
-URIDate 2016-03-31

+ Details

Name:	ifrs-full_DescriptionOfNatureOfRelatedPartyRelationship
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	ifrs-full_CategoriesOfRelatedPartiesAxis=eocc_CentralesHidroelectricasDeAysenSAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_CategoriesOfRelatedPartiesAxis=eocc_TransmisoraElectricaDeQuillotaLtdaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_CategoriesOfRelatedPartiesAxis=eocc_ElectrogasSAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_CategoriesOfRelatedPartiesAxis=eocc_GNLChileSAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_CategoriesOfRelatedPartiesAxis=eocc_GNLQuinteroSAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_CategoriesOfRelatedPartiesAxis=eocc_SouthernConePowerArgentinaSAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_CategoriesOfRelatedPartiesAxis=eocc_EnelArgentinaSAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_CategoriesOfRelatedPartiesAxis=eocc_TransmisoraElectricaDeQuillotaLtdaOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: