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

DISCONTINUED OPERATIONS Schedule of Disposal Groups, including Discontinued Operations, Income Statement, Balance Sheet and Cash Flows (Details)

DISCONTINUED OPERATIONS Schedule of Disposal Groups, including Discontinued Operations, Income Statement, Balance Sheet and Cash Flows (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
LOSS FROM DISCONTINUED OPERATIONS, net of tax	$ (928.5)	$ (140.4)
Short-term assets of discontinued operations	197.2		330.6
Long-term assets of discontinued operations	0		400.1
Short-term liabilities of discontinued operations	265.0		400.6
LONG-TERM LIABILITIES OF DISCONTINUED OPERATIONS	125.2		436.1
Depreciation, depletion and amortization	33.0	141.1
Payments to Acquire Property, Plant, and Equipment	15.9	103.3
Asset Impairment Charges, Cash Flows	76.6clf_AssetImpairmentChargesCashFlows	0clf_AssetImpairmentChargesCashFlows
North American Coal [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
LOSS FROM DISCONTINUED OPERATIONS, net of tax	(75.7)	(46.3)
Short-term assets of discontinued operations	188.6		143.8
Long-term assets of discontinued operations	0		130.4
Short-term liabilities of discontinued operations	197.7		81.3
LONG-TERM LIABILITIES OF DISCONTINUED OPERATIONS	0		125.9
Depreciation, depletion and amortization	3.2	29.9
Payments to Acquire Property, Plant, and Equipment	2.5	10.0
Asset Impairment Charges, Cash Flows	73.4	0
Eastern Canadian Iron Ore [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
LOSS FROM DISCONTINUED OPERATIONS, net of tax	(852.7)	(91.2)
Short-term assets of discontinued operations	8.6		183.5
Long-term assets of discontinued operations	0		256.0
Short-term liabilities of discontinued operations	67.3		316.3
LONG-TERM LIABILITIES OF DISCONTINUED OPERATIONS	125.2		304.6
Depreciation, depletion and amortization	0	41.2
Payments to Acquire Property, Plant, and Equipment	0	75.6
Asset Impairment Charges, Cash Flows	0	0
Other Canadian Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
LOSS FROM DISCONTINUED OPERATIONS, net of tax	(0.1)	(2.9)
Short-term assets of discontinued operations	0		3.3
Long-term assets of discontinued operations	0		13.7
Short-term liabilities of discontinued operations	0		3.0
LONG-TERM LIABILITIES OF DISCONTINUED OPERATIONS	0		5.6
Depreciation, depletion and amortization	0	0.1
Payments to Acquire Property, Plant, and Equipment	0	0
Asset Impairment Charges, Cash Flows	0	0
Canadian Entities [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
LOSS FROM DISCONTINUED OPERATIONS, net of tax	(852.8)	(94.1)
Short-term assets of discontinued operations	8.6		186.8
Long-term assets of discontinued operations	0		269.7
Short-term liabilities of discontinued operations	67.3		319.3
LONG-TERM LIABILITIES OF DISCONTINUED OPERATIONS	125.2		310.2
Depreciation, depletion and amortization	0	41.3
Payments to Acquire Property, Plant, and Equipment	0	75.6
Asset Impairment Charges, Cash Flows	0	0
Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Depreciation, depletion and amortization	3.2	71.2
Payments to Acquire Property, Plant, and Equipment	2.5	85.6
Asset Impairment Charges, Cash Flows	$ 73.4	$ 0