Quarterly report pursuant to Section 13 or 15(d)

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

v3.19.3
SEGMENT REPORTING (Reconciliation of Assets from Segment to Consolidated) (Details) - USD ($)
$ in Millions
Sep. 30, 2019
Dec. 31, 2018
Segment Reporting Information [Line Items]    
TOTAL ASSETS $ 3,491.2 $ 3,529.6
Mining and Pelletizing [Member]    
Segment Reporting Information [Line Items]    
TOTAL ASSETS 1,793.9 1,694.1
Metallics [Member]    
Segment Reporting Information [Line Items]    
TOTAL ASSETS 708.5 265.9
Operating Segments [Member]    
Segment Reporting Information [Line Items]    
TOTAL ASSETS 2,502.4 1,960.0
Corporate and Other [Member]    
Segment Reporting Information [Line Items]    
TOTAL ASSETS $ 988.8 $ 1,569.6