Commitments and Contingencies	3 Months Ended
Commitments and Contingencies	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Commitments Construction and Other Purchase Commitments. OTP has commitments under contracts, including its share of construction program and other commitments associated with its jointly-owned facilities, extending into 2046. T.O. Plastics is party to a resin supply agreement under which it must purchase all of a specified class of regrind resin delivered by the supplier at a periodically negotiated price per pound. The agreement expires in 2026. Electric Utility Capacity and Energy Requirements and Coal Purchase and Delivery Contracts. OTP has commitments for the purchase of capacity and energy requirements under agreements extending into 2044. OTP also has contracts providing for the purchase and delivery of a significant portion of its current coal requirements, with expiration dates ranging from 2022 through 2040. These contracts do not include minimum purchase requirements but do require all coal necessary for the operation of the respective plant to be purchased from the counterparty. Land Easements. OTP has commitments to make future payments under land easements extending into 2050. Contingencies FERC ROE. In November 2013 and February 2015, customers filed complaints with FERC seeking to reduce the ROE component of the transmission rates that MISO transmission owners, including OTP, may collect under the MISO tariff rate. FERC's most recent order, issued on November 19, 2020, adopted a revised ROE methodology and set the base ROE at 10.02% (10.52% with an adder) effective for the fifteen-month period from November 2013 to February 2015 and on a prospective basis beginning in September 2016. The order also dismissed any complaints covering the period from February 2015 to May 2016. The November 2020 opinion is subject to judicial review. We have deferred recognition and recorded a refund liability of $3.7 million as of March 31, 2021. This refund liability reflects our best estimate of required refunds to customers once all regulatory and judicial proceedings are finalized. Regional Haze Rule (RHR). The RHR was adopted in an effort to improve visibility in national parks and wilderness areas. The RHR requires states, in coordination with the EPA and other governmental agencies, to develop and implement plans to achieve natural visibility conditions. The second RHR implementation period covers the years 2018-2028, with state implementation plans targeted for submission to the EPA by July 31, 2021. States are required to assess reasonable progress with the RHR and determine what additional emission reductions are appropriate, if any. Coyote Station, OTP's jointly owned coal-fired power plant in North Dakota, is subject to assessment in the second implementation period under the North Dakota state implementation plan. We cannot predict with certainty the impact the state implementation plan may have on our business until the plan is finalized and adopted. However, significant emission control investments could be required, and the recovery of such costs from customers would require regulatory approval. Alternatively, investments in emission control equipment may prove to be uneconomic and result in a required early retirement of, or the sale of our interest in, Coyote Station. We cannot estimate the financial effects such a retirement or sale may have on our consolidated operating results, financial position or cash flows, but such amounts could be material and the recovery of such costs from customers would be subject to regulatory approval. Other Contingencies. We are party to litigation and regulatory enforcement matters arising in the normal course of business. We regularly analyze relevant information and, as necessary, estimate and record accrued liabilities for legal, regulatory enforcement and other matters in which a loss is probable of occurring and can be reasonably estimated. We believe the effect on our consolidated operating results, financial position and cash flows, if any, for the disposition of all matters pending as of March 31, 2021, other than those relating to the RHR, will not be material.