XML 140 R127.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Financial instruments - Long-term Energy Derivative Contracts (Detail) - Cash flow hedge | Dec. 31, 2019 MWh $ / MWh
--- | ---
PJM Western HUB |
Derivative [Line Items] |
Receive average prices (per MW-hr) | $ / MWh | 35.35
Notional quantity (MW-hrs) | MWh | 757,075
PJM NI HUB |
Derivative [Line Items] |
Receive average prices (per MW-hr) | $ / MWh | 25.54
Notional quantity (MW-hrs) | MWh | 3,443,530
ERCOT North HUB |
Derivative [Line Items] |
Receive average prices (per MW-hr) | $ / MWh | 36.46
Notional quantity (MW-hrs) | MWh | 2,665,068

X
- Definition The average strike price on the group of price risk option contracts such as put options or call options. + References No definition available. + Details
Name: | us-gaap_DerivativeAveragePriceRiskOptionStrikePrice
Namespace Prefix: | us-gaap_
Data Type: | srt-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition 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. + References No definition available. + Details
Name: | us-gaap_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Nominal number of units used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959 + Details
Name: | us-gaap_DerivativeNonmonetaryNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongTermContractForPurchaseOfElectricPowerAxis=aqunf_PJMWesternHUBExpiryDecember2022Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongTermContractForPurchaseOfElectricPowerAxis=aqunf_NIHUBExpiryDecember2022Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongTermContractForPurchaseOfElectricPowerAxis=aqunf_ERCOTNorthHUBExpiryDecember2027Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |