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

CASH FLOW INFORMATION (Narrative) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	May 01, 2015	Feb. 02, 2015	Nov. 03, 2014	Aug. 01, 2014	May 01, 2014
Dividends Payable [Line Items]
Depositary Share Interest in a Share of 7% Series A Mandatory Convertible Preferred Stock, Class A	0.025
Preferred stock cash dividend	$ 12.8us-gaap_DividendsPreferredStock	$ 12.8us-gaap_DividendsPreferredStock
Preferred Class A [Member]
Dividends Payable [Line Items]
Dividends payable, per share			$ 17.50	$ 17.50	$ 17.50	$ 17.50	$ 17.50
Preferred stock cash dividend	$ 12.8	$ 12.8
Depositary Share [Member]
Dividends Payable [Line Items]
Dividends payable, per share			$ 0.44	$ 0.44	$ 0.440	$ 0.440	$ 0.440