XML 71 R52.htm IDEA: XBRL DOCUMENT
v3.21.2

Regulatory matters - Regulatory Assets and Liabilities (Detail) - USD ($) $ in Thousands | Jun. 30, 2021 | Dec. 31, 2020
--- | --- | ---
Regulatory Liabilities [Line Items] |  |
Total regulatory assets | $ 1,115,098 | $ 845,471
Less: current regulatory assets | (100,601) | (63,042)
Non-current regulatory assets | 1,014,497 | 782,429
Total regulatory liabilities | 580,630 | 601,518
Less: current regulatory liabilities | (34,256) | (38,483)
Non-current regulatory liabilities | 546,374 | 563,035
Income taxes |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory liabilities | 310,914 | 322,317
Cost of removal |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory liabilities | 197,616 | 200,739
Pension and Postremployment benefits |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory liabilities | 32,320 | 26,311
Fuel and commodity cost adjustments |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory liabilities | 5,086 | 20,136
Rate adjustment mechanism |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory liabilities | 1,598 | 5,214
Clean energy and other customer programs |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory liabilities | 14,658 | 10,440
Rate base offset |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory liabilities | 6,053 | 6,874
Other |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory liabilities | 12,385 | 9,487
Fuel and commodity cost adjustments |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory assets | 283,941 | 18,094
Retired generating plant |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory assets | 188,586 | 194,192
Pension and Postremployment benefits |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory assets | 172,501 | 178,403
Rate adjustment mechanism |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory assets | 102,500 | 99,853
Environmental remediation |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory assets | 86,058 | 87,308
Income taxes |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory assets | 80,778 | 77,730
Debt premium |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory assets | 33,277 | 35,688
Clean energy and other customer programs |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory assets | 26,047 | 26,400
Deferred capitalized costs |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory assets | 42,376 | 34,398
Asset retirement obligation |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory assets | 26,955 | 26,546
Wildfire mitigation and vegetation management |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory assets | 25,891 | 22,736
Long-term maintenance contract |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory assets | 11,920 | 14,405
Rate review costs |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory assets | 6,872 | 8,054
Other |  |
Regulatory Liabilities [Line Items] |  |
Total regulatory assets | $ 27,396 | $ 21,664

X
- Definition The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 + Details
Name: | us-gaap_RegulatoryAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are expected to be recovered through revenue sources within one year or the normal operating cycle, if longer. Such costs are capitalized if they meet both of the following criteria: a. It is probable that future revenue in an amount at least equal to the capitalized cost will result from inclusion of that cost in allowable costs for rate-making purposes. b. Based on available evidence, the future revenue will be provided to permit recovery of the previously incurred cost rather than to provide for expected levels of similar future costs. If the revenue will be provided through an automatic rate-adjustment clause, this criterion requires that the regulator's intent clearly be to permit recovery of the previously incurred cost. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 + Details
Name: | us-gaap_RegulatoryAssetsCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 + Details
Name: | us-gaap_RegulatoryAssetsNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount for the individual regulatory liability as itemized in a table of regulatory liabilities as of the end of the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 405 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6500807&loc=d3e48068-110394 + Details
Name: | us-gaap_RegulatoryLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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_RegulatoryLiabilitiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount for the individual regulatory current liability as itemized in a table of regulatory current liabilities as of the end of the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 405 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6500807&loc=d3e48068-110394 + Details
Name: | us-gaap_RegulatoryLiabilityCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount for the individual regulatory noncurrent liability as itemized in a table of regulatory noncurrent liabilities as of the end of the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.24) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_RegulatoryLiabilityNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=aqunf_TaxesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=us-gaap_RemovalCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=us-gaap_PensionAndOtherPostretirementPlansCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=aqunf_EnergyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=aqunf_RateAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=aqunf_CustomerProgramsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=us-gaap_BaseRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=us-gaap_OtherRegulatoryAssetsLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aqunf_EnergyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aqunf_RetiredGeneratingPlantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_PensionAndOtherPostretirementPlansCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aqunf_RateAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_EnvironmentalRestorationCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aqunf_TaxesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aqunf_DebtPremiumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aqunf_CustomerProgramsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aqunf_DeferredCapitalizedCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_AssetRetirementObligationCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aqunf_WildfireMitigationAndVegetationManagementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aqunf_LongtermMaintenanceContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=aqunf_RateCaseCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_OtherRegulatoryAssetsLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |