Quarterly report pursuant to Section 13 or 15(d)

SEGMENT REPORTING (Reconciliation of Assets from Segment to Consolidated) (Details)

v3.19.2
SEGMENT REPORTING (Reconciliation of Assets from Segment to Consolidated) (Details) - USD ($)
$ in Millions
Jun. 30, 2019
Dec. 31, 2018
Segment Reporting Information [Line Items]    
TOTAL ASSETS $ 3,393.2 $ 3,529.6
Mining and Pelletizing [Member]    
Segment Reporting Information [Line Items]    
TOTAL ASSETS 1,893.9 1,694.1
Metallics    
Segment Reporting Information [Line Items]    
TOTAL ASSETS 514.7 265.9
Operating Segments [Member]    
Segment Reporting Information [Line Items]    
TOTAL ASSETS 2,408.6 1,960.0
Corporate and Other [Member]    
Segment Reporting Information [Line Items]    
TOTAL ASSETS $ 984.6 $ 1,569.6