| **Long-Term Debt (Tables)**                           | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
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| **Debt Disclosure [Abstract]**                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| Schedule Of Long-Term Debt                            | Long-term debt as of April 30, 2016, July 31, 2015 and April 30, 2015 is summarized as follows (in thousands):  Maturity (a) April 30, 2016 July 31, 2015 April 30, 2015Credit Facility Revolver 2020 $— $185,000 $—Credit Facility Term Loan 2020 243,750 250,000 —Industrial Development Bonds 2020 — — 41,200Employee Housing Bonds 2027-2039 52,575 52,575 52,5756.50% Notes 2019 — — 215,000Canyons obligation 2063 321,688 317,455 316,056Other 2016-2029 11,165 11,800 11,918Total debt   629,178 816,830 636,749Less: Current maturities (b)   13,349 10,154 256,953Long-term debt   $615,829 $806,676 $379,796(a)Maturities are based on the Company’s July 31 fiscal year end.(b)Current maturities represent principal payments due in the next 12 months. |
| Schedule Of Aggregate Maturities For Debt Outstanding | Aggregate maturities for debt outstanding as of April 30, 2016 reflected by fiscal year are as follows (in thousands): Total2016$3,269201713,354201813,397201913,4552020204,141Thereafter381,562Total debt$629,178                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |

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| - Definition
Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.
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| - Definition
Tabular disclosure of the combined aggregate amount of maturities and sinking fund requirements for all long-term borrowings for each of the five years following the date of the latest balance sheet date presented.
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