Cleveland-Cliffs Inc. Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

PROPERTY, PLANT AND EQUIPMENT (Value Of Each Of The Major Classes Of Consolidated Depreciable Assets) (Details)

PROPERTY, PLANT AND EQUIPMENT (Value Of Each Of The Major Classes Of Consolidated Depreciable Assets) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 4,174.5	$ 13,570.9
Accumulated Depreciation and Depletion, Property, Plant and Equipment	(966.6)	(2,417.5)
Property, plant and equipment, net	3,207.9	11,153.4
Land Rights And Mineral Rights [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,947.6	7,819.6
Office And Information Technology [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	80.7	125.7
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	88.9	255.2
Mining Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,399.5	1,819.3
Processing Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	361.9	2,148.6
Electric Power Facilities [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	57.4	114.3
Port Facilities [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	27.6	99.4
Interest Capitalized During Construction [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	18.8	23.8
Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	32.5	69.3
Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	65.5	104.4
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 94.1	$ 991.3