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Income Taxes Income Tax Valuation Allowance (Details 5) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Valuation Allowance [Line Items] |  |  |
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount | $ 945.8 | $ 553.5 | $ (18.7)
Valuation allowance | 1,530.5 | 584.1 |
United States Tax Cuts and Jobs Act Law [Member] |  |  |
Valuation Allowance [Line Items] |  |  |
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount | 30.7 |  |
Valuation allowance | 440.3 | $ 546.1 |
Vale Fertilizantes S.A. [Member] |  |  |
Valuation Allowance [Line Items] |  |  |
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount | $ 956.2 |  |

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- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319 + Details
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- Definition Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=84176650&loc=d3e32123-109318 + Details
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- Definition 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. + References No definition available. + Details
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