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Summary Of Significant Accounting Policies New Accounting Pronouncements (Details) - USD ($) $ in Millions | 3 Months Ended
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Jul. 31, 2017 | Jul. 31, 2016
Accounting Changes [Abstract] |  |
Prior Period Reclassification Adjustment |  | $ 17.7
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification | $ 5.1 |

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- Definition Accounting Changes [Abstract] + References No definition available. + Details
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- Definition Represents the quantification of the effect of adopting the new accounting standard or change in accounting principle expected by the entity to have a significant effect on the entity's financial statements. + References No definition available. + Details
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- Definition The amount of a reclassification adjustment made to prior period financial statement amounts. + References No definition available. + Details
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