XML 88 R70.htm IDEA: XBRL DOCUMENT
v3.20.4

Variable Interest Entities (Narrative) (Details) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2020 USD ($) Rate MW | Sep. 30, 2020 USD ($) | Jun. 30, 2020 USD ($) | Mar. 31, 2020 USD ($) | Dec. 31, 2020 USD ($) Rate MW | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($)
Variable Interest Entity [Line Items] |  |  |  |  |  |  |
Nameplate Capacity | MW | 102 |  |  |  | 102 |  |
Wind Power Purchase Agreement, Purchase Percentage | Rate | 100.00% |  |  |  | 100.00% |  |
Total Equity Membership Interest | 100.00% |  |  |  | 100.00% |  |
Obligation to the Developer | $ 69,700,000 |  |  |  | $ 69,700,000 | $ 0 | $ 0
Payment to renewable generation asset developer |  |  |  |  | 85,300,000 | 0 | 0
Total Contributions | 170,100,000 |  |  |  | 170,100,000 |  |
VIE Net Assets | 156,400,000 |  |  |  | 156,400,000 |  |
Noncontrolling interest in consolidated subsidiaries | 85,600,000 |  |  |  | 85,600,000 | 0 |
Net Income (Loss) Attributable to Noncontrolling Interest | 3,400,000 | $ 0 | $ 0 | $ 0 | 3,400,000 | $ 0 | $ 0
Expected Future Obligation to the Developer | 6,000,000.0 |  |  |  | $ 6,000,000.0 |  |
NIPSCO |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |
Cash Contribution | 700,000 |  |  |  |  |  |
Future Cash Contribution | $ 100,000 |  |  |  |  |  |
Rosewater |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |
Wind Power Purchase Agreement, Purchase Percentage | Rate | 100.00% |  |  |  | 100.00% |  |
Tax Equity Partner |  |  |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |  |  |
Cash Contribution | $ 86,100,000 |  |  |  |  |  |
Future Cash Contribution | $ 7,500,000 |  |  |  |  |  |

X
- Definition Cash Contribution + References No definition available. + Details
Name: | nix_CashContribution
Namespace Prefix: | nix_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Expected Future Obligation to the Developer + References No definition available. + Details
Name: | nix_ExpectedFutureObligationToTheDeveloper
Namespace Prefix: | nix_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Future Cash Contribution + References No definition available. + Details
Name: | nix_FutureCashContribution
Namespace Prefix: | nix_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Nameplate Capacity + References No definition available. + Details
Name: | nix_NameplateCapacity
Namespace Prefix: | nix_
Data Type: | num:powerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Obligation to the Developer + References No definition available. + Details
Name: | nix_ObligationToTheDeveloper
Namespace Prefix: | nix_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Payment to renewable generation asset developer + References No definition available. + Details
Name: | nix_PaymentToRenewableGenerationAssetDeveloper
Namespace Prefix: | nix_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Total Equity Membership Interest + References No definition available. + Details
Name: | nix_TotalEquityMembershipInterest
Namespace Prefix: | nix_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Total Expected Contributions + References No definition available. + Details
Name: | nix_TotalExpectedContributions
Namespace Prefix: | nix_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition VIE Net Assets + References No definition available. + Details
Name: | nix_VIENetAssets
Namespace Prefix: | nix_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Wind Power Purchase Agreement, Purchase Percentage + References No definition available. + Details
Name: | nix_WindPowerPurchaseAgreementPurchasePercentage
Namespace Prefix: | nix_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which is directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent (that is, noncontrolling interest, previously referred to as minority interest). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(24)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.31) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(22)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 + Details
Name: | us-gaap_MinorityInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of Net Income (Loss) attributable to noncontrolling interest. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1B -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669625-108580 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22658-107794 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669619-108580 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 55 -Paragraph 4J -URI http://asc.fasb.org/extlink&oid=120409616&loc=SL4591551-111686 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22663-107794 + Details
Name: | us-gaap_NetIncomeLossAttributableToNoncontrollingInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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_VariableInterestEntityLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=nix_NIPSCOMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=nix_RosewaterMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=nix_TaxEquityPartner
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |