Quarterly report pursuant to Section 13 or 15(d)

PROPERTY, PLANT AND EQUIPMENT (Details)

v3.20.2
PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Dec. 31, 2019
Property, Plant and Equipment [Line Items]          
Property, Plant and Equipment, Gross [1] $ 5,885.8   $ 5,885.8   $ 3,027.4
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment 1,337.9   1,337.9   1,098.4
Property, plant and equipment, net 4,547.9   4,547.9   1,929.0
Finance Lease, Right-of-Use Asset 93.7   93.7   49.0
Interest Costs Capitalized 13.6 $ 5.9 23.3 $ 9.9  
Depreciation and depletion expense 75.3 $ 20.9 110.7 $ 40.5  
Land, Land Improvements and Mineral Rights [Member]          
Property, Plant and Equipment [Line Items]          
Property, Plant and Equipment, Gross 653.2   653.2   582.2
Building [Member]          
Property, Plant and Equipment [Line Items]          
Property, Plant and Equipment, Gross 454.4   454.4   157.8
Steel and Manufacturing Equipment [Member]          
Property, Plant and Equipment [Line Items]          
Property, Plant and Equipment, Gross 2,147.9   2,147.9   42.0
Mining and Pelletizing Equipment [Member]          
Property, Plant and Equipment [Line Items]          
Property, Plant and Equipment, Gross 1,448.6   1,448.6   1,413.6
Other Assets [Member]          
Property, Plant and Equipment [Line Items]          
Property, Plant and Equipment, Gross 123.4   123.4   101.5
Construction in Progress [Member]          
Property, Plant and Equipment [Line Items]          
Property, Plant and Equipment, Gross $ 1,058.3   $ 1,058.3   $ 730.3
[1]
1 Includes right-of-use assets related to finance leases of $93.7 million and $49.0 million as of June 30, 2020 and December 31, 2019, respectively.