QUARTERLY RESULTS OF OPERATIONS (Schedule of Quarterly Financial Information) (Details) - USD ($) $ / shares in Units, $ in Millions |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2015 |
Sep. 30, 2015 |
Jun. 30, 2015 |
Mar. 31, 2015 |
Dec. 31, 2014 |
Sep. 30, 2014 |
Jun. 30, 2014 |
Mar. 31, 2014 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Revenues | $ 476.0 | $ 593.2 | $ 498.1 | $ 446.0 | $ 1,030.3 | $ 979.7 | $ 747.7 | $ 615.5 | $ 2,013.3 | $ 3,373.2 | $ 3,890.8 |
| SALES MARGIN | 43.3 | 55.1 | 57.3 | 80.8 | 256.0 | 256.2 | 183.5 | 190.0 | 236.5 | 885.7 | 1,484.4 |
| Income (Loss) from Continuing 日韩三级片, Including Portion Attributable to Noncontrolling Interest | (34.8) | 49.9 | (38.2) | 166.8 | 170.0 | (274.2) | 90.9 | 69.7 | 143.7 | 56.4 | 878.9 |
| Income (Loss) from Continuing 日韩三级片 Attributable to Noncontrolling Interest | (2.4) | 4.6 | (5.0) | 1.9 | (3.4) | (2.5) | (3.6) | 0.4 | (8.6) | (25.9) | (14.8) |
| Income (Loss) from Continuing 日韩三级片 Attributable to Parent | (37.2) | 54.5 | (43.2) | 168.7 | 166.6 | (276.7) | 87.3 | 70.1 | 135.1 | 30.5 | 864.1 |
| Income (Loss) from Discontinued 日韩三级片, Net of Tax, Attributable to Parent | (23.1) | (43.9) | 103.4 | (928.5) | (1,451.8) | (5,602.9) | (76.4) | (140.4) | (884.4) | (7,254.7) | (450.6) |
| NET INCOME (LOSS) ATTRIBUTABLE TO CLIFFS SHAREHOLDERS | (60.3) | 10.6 | 60.2 | (759.8) | (1,285.2) | (5,879.6) | 10.9 | (70.3) | (749.3) | (7,224.2) | 413.5 |
| Dividends, Preferred Stock | 听 | 听 | 听 | 听 | 听 | 听 | 听 | 听 | 38.4 | 51.2 | 48.7 |
| NET INCOME (LOSS) ATTRIBUTABLE TO CLIFFS COMMON SHAREHOLDERS | $ (60.3) | $ (15.0) | $ 60.2 | $ (772.6) | $ (1,298.0) | $ (5,892.4) | $ (1.9) | $ (83.1) | $ (787.7) | $ (7,275.4) | $ 364.8 |
| Continuing operations | $ (0.24) | $ 0.19 | $ (0.28) | $ 1.02 | $ 1.00 | $ (1.89) | $ 0.49 | $ 0.37 | $ 0.63 | $ (0.14) | $ 5.37 |
| Discontinued operations | (0.15) | (0.29) | 0.67 | (6.06) | (9.48) | (36.60) | (0.50) | (0.92) | (5.77) | (47.38) | (2.97) |
| Earnings Per Share, Basic | (0.39) | (0.10) | 0.39 | (5.04) | (8.48) | (38.49) | (0.01) | (0.55) | (5.14) | (47.52) | 2.40 |
| Continuing operations | (0.24) | 0.19 | (0.28) | 0.94 | 0.94 | (1.89) | 0.48 | 0.37 | 0.63 | (0.14) | 4.95 |
| Discontinued operations | (0.15) | (0.29) | 0.67 | (5.20) | (8.13) | (36.60) | (0.50) | (0.91) | (5.76) | (47.38) | (2.58) |
| Earnings Per Share, Diluted | $ (0.39) | $ (0.10) | $ 0.39 | $ (4.26) | $ (7.19) | $ (38.49) | $ (0.02) | $ (0.54) | $ (5.13) | $ (47.52) | $ 2.37 |
| Preferred Class A [Member] | 听 | 听 | 听 | 听 | 听 | 听 | 听 | 听 | 听 | 听 | 听 |
| Dividends, Preferred Stock | $ 0.0 | $ 25.6 | $ 0.0 | 听 | $ 12.8 | $ 12.8 | $ 12.8 | $ 12.8 | $ 38.4 | $ 51.2 | $ 48.7 |
| X | ||||||||||
- Definition Amount of paid and unpaid preferred stock dividends declared with the form of settlement in cash, stock and payment-in-kind (PIK). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of income (loss) from continuing operations attributable to the parent. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of income (loss) from continuing operations attributable to the noncontrolling interest. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses and taxes from ongoing operations before extraordinary items, and noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The amount of net income (loss) from continuing operations per each share of common stock or unit outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The amount of net income (loss) derived from continuing operations during the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount after tax of income (loss) from a discontinued operation attributable to the parent. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Per basic share amount, after tax, of income (loss) from the day-to-day business activities of the discontinued operation and gain (loss) from the disposal of the discontinued operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Per diluted share amount, after tax, of income (loss) from the day-to-day business activities of the discontinued operation and gain (loss) from the disposal of the discontinued operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Details
|