Quarterly report pursuant to Section 13 or 15(d)

SUPPLEMENTARY FINANCIAL STATEMENT INFORMATION (Revenues from Product Sales and Services) (Details)

v3.20.1
SUPPLEMENTARY FINANCIAL STATEMENT INFORMATION (Revenues from Product Sales and Services) (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Disaggregation of Revenue [Line Items]    
Realization of deferred revenue $ 34.6 $ 0.0
Revenues [1] 359.1 157.0
Steel and Manufacturing [Member]    
Disaggregation of Revenue [Line Items]    
Revenues 217.5 0.0
Steel and Manufacturing [Member] | Carbon Steel [Member]    
Disaggregation of Revenue [Line Items]    
Revenues 138.6 0.0
Steel and Manufacturing [Member] | Stainless and Electrical Steel [Member]    
Disaggregation of Revenue [Line Items]    
Revenues 59.4 0.0
Steel and Manufacturing [Member] | Other Product Lines [Member]    
Disaggregation of Revenue [Line Items]    
Revenues 19.5 0.0
Mining and Pelletizing [Member]    
Disaggregation of Revenue [Line Items]    
Revenues 141.6 157.0
Mining and Pelletizing [Member] | Iron Ore [Member]    
Disaggregation of Revenue [Line Items]    
Revenues 131.3 [2] 145.4
Mining and Pelletizing [Member] | Freight [Member]    
Disaggregation of Revenue [Line Items]    
Revenues 10.3 11.6
Automotive [Member] | Steel and Manufacturing [Member]    
Disaggregation of Revenue [Line Items]    
Revenues 120.2 0.0
Infrastructure and Manufacturing [Member] | Steel and Manufacturing [Member]    
Disaggregation of Revenue [Line Items]    
Revenues 44.0 0.0
Distributors and Converters [Member] | Steel and Manufacturing [Member]    
Disaggregation of Revenue [Line Items]    
Revenues 53.3 0.0
Steel Producers [Member] | Mining and Pelletizing [Member]    
Disaggregation of Revenue [Line Items]    
Revenues 141.6 [2] 157.0
Non-US [Member]    
Disaggregation of Revenue [Line Items]    
Revenues $ 46.7 $ 43.0
[1]
1 Includes Realization of deferred revenue of $34.6 million for the three months ended March 31, 2020.
[2]
1 Includes Realization of deferred revenue of $34.6 million for the three months ended March 31, 2020.