DERIVATIVE INSTRUMENTS AND HEDGING (Details) $ in Millions	3 Months Ended
DERIVATIVE INSTRUMENTS AND HEDGING (Details) $ in Millions	Mar. 31, 2026 USD ($) MWh Tons MMBtu	Dec. 31, 2025 Tons MWh MMBtu
Commodity Contract
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Reclassification of net losses	$ (10)
Commodity Contract \| Natural Gas
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amount \| MMBtu	137,225,000	139,300,000
Commodity Contract \| Electricity
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amount \| MWh	1,868,208	1,974,380
Commodity Contract \| HRC
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amount \| Tons	375,300	220,220
Cash-Settled Sales Swaps
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Reclassification of net losses	$ (40)

- 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 + Details

CLEVELAND-CLIFFS INC. 10-Q