|
Basis Of Presentation And Significant Accounting Policies (Schedule Of Subsidiaries) (Details)
|
3 Months Ended | |
|---|---|---|
|
Mar. 31, 2012
|
Mar. 31, 2011
|
|
|
Northshore [Member]
|
Ìý | Ìý |
| Related Party Transaction [Line Items] | Ìý | Ìý |
| Location | Minnesota | Ìý |
| Ownership interest, percent | 100.00% | Ìý |
| Operation | Iron Ore | Ìý |
|
United Taconite [Member]
|
Ìý | Ìý |
| Related Party Transaction [Line Items] | Ìý | Ìý |
| Location | Minnesota | Ìý |
| Ownership interest, percent | 100.00% | Ìý |
| Operation | Iron Ore | Ìý |
|
Wabush [Member]
|
Ìý | Ìý |
| Related Party Transaction [Line Items] | Ìý | Ìý |
| Location | Labrador/Quebec, Canada | Ìý |
| Ownership interest, percent | 100.00% | Ìý |
| Operation | Iron Ore | Ìý |
|
Bloom Lake [Member]
|
Ìý | Ìý |
| Related Party Transaction [Line Items] | Ìý | Ìý |
| Location | Quebec, Canada | Ìý |
| Ownership interest, percent | 75.00% | 75.00% |
| Operation | Iron Ore | Ìý |
|
Tilden [Member]
|
Ìý | Ìý |
| Related Party Transaction [Line Items] | Ìý | Ìý |
| Location | Michigan | Ìý |
| Ownership interest, percent | 85.00% | 85.00% |
| Operation | Iron Ore | Ìý |
|
Empire [Member]
|
Ìý | Ìý |
| Related Party Transaction [Line Items] | Ìý | Ìý |
| Location | Michigan | Ìý |
| Ownership interest, percent | 79.00% | 79.00% |
| Operation | Iron Ore | Ìý |
|
Koolyanobbing [Member]
|
Ìý | Ìý |
| Related Party Transaction [Line Items] | Ìý | Ìý |
| Location | Western Australia | Ìý |
| Ownership interest, percent | 100.00% | Ìý |
| Operation | Iron Ore | Ìý |
|
Pinnacle [Member]
|
Ìý | Ìý |
| Related Party Transaction [Line Items] | Ìý | Ìý |
| Location | West Virginia | Ìý |
| Ownership interest, percent | 100.00% | Ìý |
| Operation | Coal | Ìý |
|
Oak Grove [Member]
|
Ìý | Ìý |
| Related Party Transaction [Line Items] | Ìý | Ìý |
| Location | Alabama | Ìý |
| Ownership interest, percent | 100.00% | Ìý |
| Operation | Coal | Ìý |
|
CLCC [Member]
|
Ìý | Ìý |
| Related Party Transaction [Line Items] | Ìý | Ìý |
| Location | West Virginia | Ìý |
| Ownership interest, percent | 100.00% | Ìý |
| Operation | Coal | Ìý |