v3.8.0.1

Financial risk management (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Interest Rate Risk [Member] |  |  |
Financial risk management [Abstract] |  |  |
Forecasted increase in benchmark interest rate | 0.25% |  |
Forecasted loss on cash flow hedges due to increase in benchmark interest rate | $ (228) | $ (2,563) | $ (1,795)
Forecasted increase in hedging reserves due to increase in benchmark interest rate | $ 37,767 | $ 37,290 | $ 41,702
Interest Rate Risk [Member] | Euros [Member] |  |  |
Financial risk management [Abstract] |  |  |
Maturity date | 2030 |  |
Interest Rate Risk [Member] | Euros [Member] | Bottom of Range [Member] |  |  |
Financial risk management [Abstract] |  |  |
Percentage of notional amount of debt hedged | 87.00% |  |
Interest rate | 3.20% |  |
Interest Rate Risk [Member] | Euros [Member] | Top of Range [Member] |  |  |
Financial risk management [Abstract] |  |  |
Percentage of notional amount of debt hedged | 100.00% |  |
Interest rate | 4.87% |  |
Interest Rate Risk [Member] | U.S. Dollars [Member] |  |  |
Financial risk management [Abstract] |  |  |
Maturity date | 2032 |  |
Interest Rate Risk [Member] | U.S. Dollars [Member] | Bottom of Range [Member] |  |  |
Financial risk management [Abstract] |  |  |
Percentage of notional amount of debt hedged | 70.00% |  |
Interest rate | 2.32% |  |
Interest Rate Risk [Member] | U.S. Dollars [Member] | Top of Range [Member] |  |  |
Financial risk management [Abstract] |  |  |
Percentage of notional amount of debt hedged | 100.00% |  |
Interest rate | 5.27% |  |
Currency Risk [Member] |  |  |
Financial risk management [Abstract] |  |  |
Net Euro exposure percentage for next fiscal year | 100.00% |  |
Net Euro exposure percentage for following fiscal period | 75.00% |  |

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

X
- Definition The forecasted gain (loss) on cash flow hedges attributable to a change in the benchmark interest rate. + References No definition available. + Details
Name: | aby_ForecastedGainLossOnCashFlowHedgesDueToChangeInBenchmarkInterestRate
Namespace Prefix: | aby_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The forecasted increase (decrease) in the benchmark interest rate used to calculate the impact of interest rate derivative positions on the income statement, assuming all other variables remain constant. + References No definition available. + Details
Name: | aby_ForecastedIncreaseDecreaseInBenchmarkInterestRate
Namespace Prefix: | aby_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The forecasted increase (decrease) in hedging reserves attributable to a change in the benchmark interest rate. + References No definition available. + Details
Name: | aby_ForecastedIncreaseDecreaseInHedgingReservesDueToChangeInBenchmarkInterestRate
Namespace Prefix: | aby_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Refers to net value exposure percentage for the next fiscal year. + References No definition available. + Details
Name: | aby_NetValueExposurePercentageForNextTwelveMonths
Namespace Prefix: | aby_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Refers to net value exposure percentage in the year following the latest fiscal year. + References No definition available. + Details
Name: | aby_NetValueExposurePercentageYearTwo
Namespace Prefix: | aby_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The percentage of the notional amount of the entity's debt hedged with interest rate swaps and options. + References No definition available. + Details
Name: | aby_PercentageOfNotionalAmountOfDebtHedged
Namespace Prefix: | aby_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The interest rate on borrowings. [Refer: Borrowings] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IFRS -Number 7 -IssueDate 2016-01-13 -Paragraph 7 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2016-03-30&anchor=para_7&doctype=Standard -URIDate 2016-03-31 + Details
Name: | ifrs-full_BorrowingsInterestRate
Namespace Prefix: | ifrs-full_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The maturity of borrowings. [Refer: Borrowings] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IFRS -Number 7 -IssueDate 2016-01-13 -Paragraph 7 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2016-03-30&anchor=para_7&doctype=Standard -URIDate 2016-03-31 + Details
Name: | ifrs-full_BorrowingsMaturity
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_TypesOfRisksAxis=ifrs-full_InterestRateRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CurrencyAxis=currency_EUR
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_BottomOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_TopOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CurrencyAxis=currency_USN
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfRisksAxis=ifrs-full_CurrencyRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |