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SUBSEQUENT EVENTS SUBSEQUENT EVENTS (Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended |  |  |
--- | --- | --- | --- | ---
Sep. 30, 2017 | Jul. 18, 2017 | Jun. 30, 2017 | Dec. 31, 2016
Subsequent Event [Line Items] |  |  |  |
Contingent Liabilities recognized in Consolidated Financials |  |  | $ 38.5 | $ 37.2
Wabush Scully Mine Sale [Domain] |  |  |  |
Subsequent Event [Line Items] |  |  |  |
Contingent Liabilities recognized in Consolidated Financials |  | $ 38.5 |  |
Scenario, Forecast [Member] | Wabush Scully Mine Sale [Domain] |  |  |  |
Subsequent Event [Line Items] |  |  |  |
Gain on Sale of Wabush Scully Mine | $ 30.0 |  |  |

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- Definition Contingent Liabilities recognized in Consolidated Financials + References No definition available. + Details
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- Definition Gain on Sale of Wabush Scully Mine + References No definition available. + Details
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- Definition Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event. + References No definition available. + Details
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- Details
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- Details
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