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Stockholders' Equity (Details) - USD ($) $ in Thousands			6 Months Ended
	Jan. 26, 2022	May 03, 2021	Jun. 30, 2022	Dec. 31, 2021
Class of Stock [Line Items]
Total capitalization			$ 1,940,242	$ 1,724,791
Otter Tail Power Company
Class of Stock [Line Items]
Equity to total capitalization ratio			52.20%
Net assets restricted from distribution			$ 714,400
Minimum | Otter Tail Power Company | Minnesota Public Utilities Commission
Class of Stock [Line Items]
Public utilities, requested equity capital structure, percentage	48.00%
Maximum | Otter Tail Power Company
Class of Stock [Line Items]
Total capitalization			$ 1,700,000
Maximum | Otter Tail Power Company | Minnesota Public Utilities Commission
Class of Stock [Line Items]
Public utilities, requested equity capital structure, percentage	58.70%
Second Shelf Registration
Class of Stock [Line Items]
Shelf registration (in shares)		1,500,000
Number of shares issued (in shares)			70,369
Number of shares available for grant (in shares)			1,314,451

X

- Definition

Represents the ratio of Equity to total capitalization, which includes as equity minority interest and preferred stock as well as all of the components of common equity as presented on the balance sheet. Total capitalization is calculated as equity plus short-term debt plus long-term debt as presented on the balance sheet.

+ References

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- Definition

Represents net assets restricted from distribution.

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+ References

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- Definition

This element represents the total consolidated (as applicable) capitalization of the entity which is comprised of its long-term debt and equity instruments. The table may be detailed by subsidiary (legal entity) and include information by type of debt or equity detailed by instrument.

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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.

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- Definition

Percentage of public utility's requested equity to capital, including debt and equity.

+ References

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- Definition

The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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