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Equity Investments - Investment in Nobles 2 (Details) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2022 USD ($) MW | Mar. 31, 2021 USD ($) | Dec. 31, 2021 USD ($)
Investment in Nobles 2 [Line Items] |  |  |  |
Equity Investment Balance |  | $ 320.6 |  | $ 318.0
Cash Investments |  | 2.7 | $ 1.0 |
Equity Earnings |  | 5.5 | 4.8 |
Net Loss Attributable to Non-Controlling Interest |  | $ (19.8) | $ (8.4) |
Nobles 2 [Member] |  |  |  |
Investment in Nobles 2 [Line Items] |  |  |  |
Ownership Percentage |  | 49.00% |  |
Equity Investment Balance |  | $ 162.1 |  | $ 163.5
Distributed Earnings |  | (1.5) |  |
Equity Earnings | [1] | 0.1 |  |
Net Loss Attributable to Non-Controlling Interest |  | $ 3.2 |  |
Wind Turbine Generators [Member] | Tenaska [Member] | Minnesota Power [Member] | Tenaska PPA [Member] |  |  |  |
Investment in Nobles 2 [Line Items] |  |  |  |
Generating Capacity Counterparty Owned (MW) | MW |  | 250 |  |
Long-term Contract for Purchase of Electric Power, Term of Contract (Years) |  | 20 years |  |
[1] | The Company also recorded net loss attributable to non-controlling interest of $3.2 million related to its investment in Nobles 2.

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