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

DERIVATIVE INSTRUMENTS (Narrative) (Details)

v3.8.0.1

DERIVATIVE INSTRUMENTS (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Derivative [Line Items]
Derivative Asset, Current	$ 89.5		$ 89.5		$ 33.1
Derivative Liability, Current	9.3		9.3		0.5
Customer Supply Agreement [Member] \| Not Designated as Hedging Instrument [Member] \| Product Revenues [Member]
Derivative [Line Items]
Amount of gain/(loss) recognized in income on derivative	54.4	$ 7.1	123.6	$ 26.8
Customer Supply Agreement [Member] \| Not Designated as Hedging Instrument [Member] \| Derivative Financial Instruments, Assets [Member]
Derivative [Line Items]
Derivative Asset, Current	84.8		84.8		21.3
Provisional Pricing Arrangements [Member] \| Not Designated as Hedging Instrument [Member] \| U S Iron Ore And Asia Pacific Iron Ore [Member] \| Product Revenues [Member]
Derivative [Line Items]
Amount of gain/(loss) recognized in income on derivative	13.1	$ 4.5	32.9	$ 22.9
Provisional Pricing Arrangements [Member] \| Not Designated as Hedging Instrument [Member] \| U S Iron Ore And Asia Pacific Iron Ore [Member] \| Derivative Financial Instruments, Assets [Member]
Derivative [Line Items]
Derivative Asset, Current	4.7		4.7		10.3
Provisional Pricing Arrangements [Member] \| Not Designated as Hedging Instrument [Member] \| U S Iron Ore And Asia Pacific Iron Ore [Member] \| Derivative Financial Instruments, Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Current	$ 9.3		$ 9.3		$ 0.5

- Definition

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13495-108611

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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- Definition

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
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- Definition

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section 50
-Paragraph 3
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