SEGMENT REPORTING (Narrative) (Details)	6 Months Ended
Jun. 30, 2015 Facility
U.S. Iron Ore [Member]
Segment Reporting Information [Line Items]
Number of mines (in number of facilities)	5
Asia Pacific Iron Ore [Member]
Segment Reporting Information [Line Items]
Number of mines (in number of facilities)	1

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration