Assets Held for Sale - Narrative (Details) - El Arrayan SPA [Member] - Discontinued Operations, Held-for-sale [Member] $ in Millions	6 Months Ended
Jun. 30, 2018 USD ($)	May 21, 2018 USD ($) km MW
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership interest		71.00%
Distance of facility from Santiago \| km		400
Generating capacity \| MW		81
Cash consideration		$ 68.5
Impairment loss	$ 4.2

Disposal Group, Including Discontinued Operation, Distance Of Facility From Santiago, Chile

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- Definition

Disposal Group, Including Discontinued Operation, Generating Capacity

+ References

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- Definition

Disposal Group, Including Discontinued Operation, Ownership Interest Held, Percentage

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- Definition

Amount after tax of (gain) loss recognized for the (reversal of write-down) write-down to fair value, less cost to sell, of a discontinued operation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=65878427&loc=d3e957-107759

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-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
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-Section 50
-Paragraph 5C
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721675-107760

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=64827811&loc=d3e1361-107760

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Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

+ References

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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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No definition available.

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