Cleveland-Cliffs Inc. Annual report pursuant to Section 13 and 15(d)

Related Parties (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 years	Dec. 31, 2010	Dec. 31, 2002	Dec. 31, 2011 Noncurrent Assets [Member]	Dec. 31, 2010 Noncurrent Assets [Member]	Dec. 31, 2011 Empire [Member]	Dec. 31, 2010 Empire [Member]	Dec. 31, 2002 Empire [Member]	Dec. 31, 2001 Empire [Member]
Related Party Transaction [Line Items]
Accounts receivable and derivative assets related parties	$ 180.4	$ 52.4
Other current liabilities related parties	43.0
Present value of other non-current assets				16.5	22.8
Percent ownership interest								46.70%	46.70%
Noncontrolling Interest, Ownership Percentage by Parent								79.00%
Indemnified obligations of related parties			120.0
Present value of receivable						$ 26.5	$ 32.8
Life of the supply agreement, years	12

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.