v3.8.0.1

Project debt, Movements of project debt (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016
Project Debt - Long Term [Abstract] |  |
Beginning balance | $ 4,629,184 | $ 3,574,464
Increases | 52,027 | 36,842
Decreases | (42,560) | 0
Currency translation differences | 316,646 | (64,426)
Reclassifications | 273,620 | 1,082,304
Ending balance | 5,228,917 | 4,629,184
Project Debt - Short Term [Abstract] |  |
Beginning balance | 701,283 | 1,896,205
Increases | 304,707 | 329,434
Decreases | (509,131) | (480,969)
Currency translation differences | 23,052 | 38,917
Reclassifications | (273,620) | (1,082,304)
Ending balance | 246,291 | 701,283
Total Project Debt [Abstract] |  |
Beginning balance | 5,330,467 | 5,470,669
Increases | 356,734 | 366,276
Decreases | (551,691) | (480,969)
Currency translation differences | 339,698 | (25,509)
Reclassifications | 0 | 0
Ending balance | $ 5,475,208 | $ 5,330,467

X
- Definition The amount of exchange gains (losses) that arise from foreign currency transactions on long-term project debt. + References No definition available. + Details
Name: | aby_CurrencyTranslationGainsLossesOnLongTermProjectDebt
Namespace Prefix: | aby_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of exchange gains (losses) that arise from foreign currency transactions on long-term and short-term project debt. + References No definition available. + Details
Name: | aby_CurrencyTranslationGainsLossesOnProjectDebt
Namespace Prefix: | aby_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of exchange gains (losses) that arise from foreign currency transactions on short-term project debt. + References No definition available. + Details
Name: | aby_CurrencyTranslationGainsLossesOnShortTermProjectDebt
Namespace Prefix: | aby_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of current project debt issued at the project level under project finance. + References No definition available. + Details
Name: | aby_CurrentProjectDebt
Namespace Prefix: | aby_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The current and non-current portions of project debt issued at the project level under project finance. + References No definition available. + Details
Name: | aby_LongTermAndShortTermProjectDebt
Namespace Prefix: | aby_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The non-current portion of non-current project debt issued at the project level under project finance. + References No definition available. + Details
Name: | aby_NoncurrentPortionOfNoncurrentProjectDebt
Namespace Prefix: | aby_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The cash inflow from non-current and current borrowings obtained. + References No definition available. + Details
Name: | aby_ProceedsFromBorrowings
Namespace Prefix: | aby_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | aby_ProjectDebtLongTermAbstract
Namespace Prefix: | aby_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | aby_ProjectDebtShortTermAbstract
Namespace Prefix: | aby_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of project debt reclassified into (out of) long-term from (to) short-term. + References No definition available. + Details
Name: | aby_ReclassificationIntoOutOfLongTermProjectDebt
Namespace Prefix: | aby_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of project debt reclassified into (out of) short-term from (to) long-term. + References No definition available. + Details
Name: | aby_ReclassificationIntoOutOfShortTermProjectDebt
Namespace Prefix: | aby_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of project debt reclassified between short-term and long-term. + References No definition available. + Details
Name: | aby_ReclassificationOfProjectDebt
Namespace Prefix: | aby_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash outflow to settle non-current and current borrowings. + References No definition available. + Details
Name: | aby_RepaymentsOfBorrowings
Namespace Prefix: | aby_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | aby_TotalProjectDebtAbstract
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Balance Type: | na
Period Type: | duration

X
- Definition The cash inflow from current borrowings obtained. [Refer: Current borrowings] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 7 -IssueDate 2016-01-13 -Paragraph 17 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=7&date=2016-03-30&anchor=para_17&doctype=Standard -URIDate 2016-03-31 + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- Definition The cash inflow from non-current borrowings obtained. [Refer: Borrowings] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 7 -IssueDate 2016-01-13 -Paragraph 17 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=7&date=2016-03-30&anchor=para_17&doctype=Standard -URIDate 2016-03-31 + Details
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Balance Type: | debit
Period Type: | duration

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- Definition The cash outflow for repayments of current borrowings. [Refer: Current borrowings] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 7 -IssueDate 2016-01-13 -Paragraph 17 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=7&date=2016-03-30&anchor=para_17&doctype=Standard -URIDate 2016-03-31 + Details
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Period Type: | duration

X
- Definition The cash outflow for repayments of non-current borrowings. [Refer: Borrowings] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 7 -IssueDate 2016-01-13 -Paragraph 17 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=7&date=2016-03-30&anchor=para_17&doctype=Standard -URIDate 2016-03-31 + Details
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Period Type: | duration