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OPERATIONS AND SIGNIFICANT ACCOUNTING POLICIES - Other Non-Current Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Business Segments [Line Items]
Asset Retirement Obligation	$ 263.3	$ 261.3
PSAs	12.2	15.1
Other	35.9	36.4
Total Other Non-Current Liabilities	311.4	312.8
BNI Energy
Business Segments [Line Items]
Other receivables	$ 42.3	$ 42.3

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- Definition

The fair value adjustment for the price of power per MW at market rates compared to those at contract rate at the time of acquisition through the end of the contract term present valued to acquisition date resulting in a noncurrent liability.

+ References

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Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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