XML 154 R124.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Schedule I - Condensed Financial Information of Registrant - Schedule of Related Party Transactions (Details) - USD ($) $ in Thousands | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Related Party Transaction [Line Items] |  |
Accounts Receivable | $ 145,964 | $ 157,143
Accounts Payable | 113,574 | 94,428
Otter Tail Corporation | Subsidiaries |  |
Related Party Transaction [Line Items] |  |
Accounts Receivable | 5,642 | 2,555
Interest Receivable | 117 | 117
Current Notes Receivable | 4,706 | 0
Long-Term Notes Receivable | 78,900 | 78,900
Accounts Payable | 7 | 7
Current Notes Payable | 752,625 | 568,672
Otter Tail Corporation | Subsidiaries | Otter Tail Power Company |  |
Related Party Transaction [Line Items] |  |
Accounts Receivable | 5,223 | 2,415
Interest Receivable | 0 | 0
Current Notes Receivable | 0 | 0
Long-Term Notes Receivable | 0 | 0
Accounts Payable | 7 | 7
Current Notes Payable | 0 | 0
Otter Tail Corporation | Subsidiaries | Northern Pipe Products, Inc. |  |
Related Party Transaction [Line Items] |  |
Accounts Receivable | 36 | 0
Interest Receivable | 7 | 7
Current Notes Receivable | 0 | 0
Long-Term Notes Receivable | 5,000 | 5,000
Accounts Payable | 0 | 0
Current Notes Payable | 66,170 | 56,917
Otter Tail Corporation | Subsidiaries | Vinyltech Corporation |  |
Related Party Transaction [Line Items] |  |
Accounts Receivable | 0 | 14
Interest Receivable | 17 | 17
Current Notes Receivable | 0 | 0
Long-Term Notes Receivable | 11,500 | 11,500
Accounts Payable | 0 | 0
Current Notes Payable | 90,764 | 98,016
Otter Tail Corporation | Subsidiaries | BTD Manufacturing, Inc. |  |
Related Party Transaction [Line Items] |  |
Accounts Receivable | 0 | 0
Interest Receivable | 78 | 78
Current Notes Receivable | 0 | 0
Long-Term Notes Receivable | 52,000 | 52,000
Accounts Payable | 0 | 0
Current Notes Payable | 5,662 | 6,291
Otter Tail Corporation | Subsidiaries | T.O. Plastics, Inc. |  |
Related Party Transaction [Line Items] |  |
Accounts Receivable | 42 | 36
Interest Receivable | 15 | 15
Current Notes Receivable | 4,706 | 0
Long-Term Notes Receivable | 10,400 | 10,400
Accounts Payable | 0 | 0
Current Notes Payable | 0 | 980
Otter Tail Corporation | Subsidiaries | Varistar Corporation |  |
Related Party Transaction [Line Items] |  |
Accounts Receivable | 0 | 0
Interest Receivable | 0 | 0
Current Notes Receivable | 0 | 0
Long-Term Notes Receivable | 0 | 0
Accounts Payable | 0 | 0
Current Notes Payable | 590,029 | 406,468
Otter Tail Corporation | Subsidiaries | Otter Tail Assurance Limited |  |
Related Party Transaction [Line Items] |  |
Accounts Receivable | 341 | 90
Interest Receivable | 0 | 0
Current Notes Receivable | 0 | 0
Long-Term Notes Receivable | 0 | 0
Accounts Payable | 0 | 0
Current Notes Payable | $ 0 | $ 0

X
- Definition Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(19)(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 852 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481372/852-10-55-10 + Details
Name: | us-gaap_AccountsPayableCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 310 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477802/946-310-45-1 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(5)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(5)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 954 -SubTopic 310 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479196/954-310-45-1 Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(3)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 + Details
Name: | us-gaap_AccountsReceivableNet
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 current interest earned but not received. Also called accrued interest or accrued interest receivable. For classified balance sheets, represents the current amount receivable, that is amounts expected to be collected within one year or the normal operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(3)(a)(4)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_InterestReceivableCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Sum of the carrying values as of the balance sheet date of the portions of long-term notes payable due within one year or the operating cycle if longer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(20)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(19)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_NotesPayableCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, after allowance for credit loss, of receivable classified as other and noncurrent. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(17)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_OtherReceivableAfterAllowanceForCreditLossNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, after allowance, of receivables classified as other, due within one year or the operating cycle, if longer. + References No definition available. + Details
Name: | us-gaap_OtherReceivablesNetCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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 Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 13 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481990/310-10-45-13 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(c)(2)(i)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(c)(2)(ii)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(g)(3)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1 + Details
Name: | us-gaap_RelatedPartyTransactionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_RelatedPartyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=ottr_OtterTailPowerCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=ottr_NorthernPipeProductsIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=ottr_VinyltechCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=ottr_BTDManufacturingIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=ottr_TOPlasticsIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=ottr_VaristarCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=ottr_OtterTailAssuranceLimitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |