v3.25.2
COMMITMENTS - Narrative (Details)
$ in Millions
 6 Months Ended 12 Months Ended
Feb. 28, 2024
Jun. 30, 2025
USD ($)
tonne
Dec. 31, 2024
USD ($)
Disclosure of commitments [line items]      
Commitments in relation to associates   $ 876 $ 1,704
Commitments in relation to joint ventures   2,483 719
Provision of guarantees or collateral by entity, third party transactions   315 256
Pledges of property, plant and equipment   68 33
Other commitments   1,870 1,294
Supply commitment, remaining minimum amount committed   $ 2,865 2,897
Offtake agreement, period   25 years  
Kryvyi Rih Industrial Gas      
Disclosure of commitments [line items]      
Commitments in relation to associates     798
Serra Azul Mine, Brazil      
Disclosure of commitments [line items]      
Contractual capital commitments   $ 11 12
Expected capacity of DRI pellet feed (in tonnes) | tonne   4,500,000  
ArcelorMittal Brasil S.A.      
Disclosure of commitments [line items]      
Expected costs to be in compliance with the ECA   $ 17 12
Maximum fine for non-compliance with agreement   18 16
Other commitments   1,168 295
ArcelorMittal Liberia Ltd      
Disclosure of commitments [line items]      
Contractual capital commitments   $ 200 257
Concentrate sinter fines capacity (in tonnes) | tonne   20,000,000  
State of the Grand-Duchy of Luxembourg      
Disclosure of commitments [line items]      
Percentage of headquarters entity is committed to acquire 50.00%    
5.146 billion 10-year term loan      
Disclosure of commitments [line items]      
Percent guaranteed   60.00%  
Asset-based revolving credit facility | Operating subsidiaries | South Africa      
Disclosure of commitments [line items]      
Debt instrument, collateral amount   $ 197  
Debt instrument, ceded bank accounts to secure environmental obligations, true sale of receivables programs and revolving base finance facility   107  
Total for all associates      
Disclosure of commitments [line items]      
Provision of guarantees or collateral by entity, related party transactions   0 11
Commitments within sureties, guarantees, LOC, pledges, and other collateral   265 291
Total for all joint ventures      
Disclosure of commitments [line items]      
Provision of guarantees or collateral to entity, related party transactions   5,316 6,259
Commitments within sureties, guarantees, LOC, pledges, and other collateral   103 404
Tameh      
Disclosure of commitments [line items]      
Commitments in relation to joint ventures   285 287
Enerfos      
Disclosure of commitments [line items]      
Commitments in relation to joint ventures   409 380
Calvert | Total for all joint ventures      
Disclosure of commitments [line items]      
Provision of guarantees or collateral to entity, related party transactions   0 1,183
Al Jubail | Total for all joint ventures      
Disclosure of commitments [line items]      
Provision of guarantees or collateral to entity, related party transactions   162 186
Ventos de Santo Antonio Comercializadora de Energia S.A. ("VdSA") | Total for all joint ventures      
Disclosure of commitments [line items]      
Provision of guarantees or collateral to entity, related party transactions   350 183
Global Chartering Limited      
Disclosure of commitments [line items]      
Counter guarantees   270 303
ArcelorMittal Nippon Steel India Limited      
Disclosure of commitments [line items]      
Supply commitment, remaining minimum amount committed   2,781 2,787
ArcelorMittal Nippon Steel India Limited | Total for all joint ventures      
Disclosure of commitments [line items]      
Provision of guarantees or collateral to entity, related party transactions   4,144 $ 4,038
Ventos de Santo Antônio Comercializadora de Energia (VdSA)      
Disclosure of commitments [line items]      
Commitments in relation to joint ventures   $ 1,739