| **Stockholders' Equity (Tables)**                              | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
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| **Stockholders' Equity Note [Abstract]**                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| Schedule Of Capital Stock                                      | Changes in common stock for the nine months ended July 31, 2016 are as follows.In thousandsShares AmountBalance, October 31, 201580,883 $721,419Issued to participants in the Employee Stock Purchase Plan (ESPP)17 962Issued to participants in the Dividend Reinvestment and Stock Purchase Plan (DRIP)253 14,352Issued to participants in the ICP130 7,486Costs from issuance of common stock  (88)Balance, July 31, 201681,283$744,131                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| Dividends Paid                                                 | Cash dividends paid per share of common stock for the three months and nine months ended July 31, 2016 and 2015 are as follows.  Three Months Nine Months 2016 2015 2016 2015Cash dividends paid per share of common stock$0.34 $0.33 $1.01 $0.98                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| Accumulated Other Comprehensive Income (Loss)                  | Changes in each component of accumulated OCIL are presented below for the three months and nine months ended July 31, 2016 and 2015.  Changes in Accumulated OCIL(1) Three Months Nine MonthsIn thousands2016 2015 2016 2015Accumulated OCIL beginning balance, net of tax$(640) $(970) $(855) $(237)Hedging activities of equity method investments:        OCIL before reclassifications, net of tax102 33 (360) (1,227) Amounts reclassified from accumulated OCIL, net of tax206 307 881 872Total current period activity of hedging activities of equity method investments, net of tax308340521(355)Net current period benefit activities of equity method investments, net of tax(12) 2(10) (36)Accumulated OCIL ending balance, net of tax$(344)$(628)$(344)$(628)        (1) Amounts in parentheses indicate debits to accumulated OCIL.                                                                                                                                                                                                                                                                                              |
| Reclassification Out Of Accumulated Other Comprehensive Income | A reconciliation of the effect on certain line items of net income on amounts reclassified out of each component of accumulated OCIL is presented below for the three months and nine months ended July 31, 2016 and 2015. Reclassification Out of Accumulated OCIL (1) Affected Line Items on CondensedStatements of Operations and Comprehensive Income Three Months Nine Months In thousands2016 2015 2016 2015 Hedging activities of equity method investments$330 $505 $1,438 $1,430 Income from equity method investmentsIncome tax expense(124) (198) (557) (558) Income taxesHedging activities of equity method investments206307 881 872  Net benefit activities of equity method investments(19) 3 (15) (60) Income from equity method investmentsIncome tax expense7 (1) 5 24 Income taxesNet benefit activities of equity method investments(12) 2 (10) (36)  Total reclassification for the period, net of tax$194 $309 $871 $836            (1) Amounts in parentheses indicate debits to accumulated OCIL.  |

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Tabular disclosure of information related to dividends declared, including paid and unpaid dividends.
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Tabular disclosure of information about items reclassified out of accumulated other comprehensive income (loss).
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| - Definition
Tabular disclosure of the components of accumulated other comprehensive income (loss).
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Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=66004124&loc=SL7669686-108580
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Tabular disclosure of the change in common stock outstanding.
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