| **Business Segments**            | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      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| **Segment Reporting [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                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| Business Segments                | Business SegmentsWe have three reportable business segments, regulated utility, regulated non-utility and unregulated non-utility activities. Our segments are identified based on products and services, regulatory environments and our current corporate organization and business decision-making activities. The regulated utility segment is the gas distribution business, where we include the operations of merchandising and its related service work and home service agreements, with activities conducted by the parent company. Although the operations of our regulated utility segment are located in three states under the jurisdiction of individual state regulatory commissions, the operations are managed as one unit having similar economic and risk characteristics within one company. Operations of our regulated non-utility activities segment are comprised of our equity method investments in joint ventures with regulated activities that are held by our wholly-owned subsidiaries. Operations of our unregulated non-utility activities segment are comprised primarily of our equity method investment in a joint venture with unregulated activities that is held by a wholly-owned subsidiary; activities of our other minor subsidiaries are also included.Operations of the regulated utility segment are reflected in “Operating Income” in the Condensed Consolidated Statements of Operations and Comprehensive Income. Operations of the regulated non-utility activities and unregulated non-utility activities segments are included in the Condensed Consolidated Statements of Operations and Comprehensive Income in “Other Income (Expense)” in “Income from equity method investments” and “Non-operating income.”Our chief operating decision maker is the executive management team. We produce consolidated financial information internally that is supplemented with separate non-utility activity reporting that is used regularly to make operating decisions and assess performance of our three business segments. We evaluate the performance of the regulated utility segment based on margin, operations and maintenance expenses and operating income. We evaluate the performance of the regulated and unregulated non-utility activities segments based on earnings and cash flows from the ventures. The basis of segmentation and the basis of the measurement of segment profit or loss are the same as reported in the consolidated financial statements in our Form 10-K for the year ended October 31, 2015.Operations by segment for the three months and nine months ended July 31, 2016 and 2015 are presented below. Regulated Utility Regulated Non-UtilityActivities Unregulated Non-UtilityActivities TotalIn thousands2016 2015 2016 2015 2016 2015 2016 2015Three Months               Revenues from external customers$157,806 $158,266 $— $— $— $— $157,806 $158,266Margin114,771 111,572 — — — — 114,771 111,572Operations and maintenance expenses68,867 69,587 16 19 58 49 68,941 69,655Income from equity method investments— — 1,229 3,894 3,009 1,907 4,238 5,801Operating income (loss) before income taxes316 (1,864) (121) (89) (76) (68) 119 (2,021)Income (loss) before income taxes(15,233) (18,904) 1,108 3,805 2,932 1,839 (11,193) (13,260)Nine Months             Revenues from external customers$969,329 $1,190,462 $— $— $— $— $969,329 $1,190,462Margin625,385 607,263 — — — — 625,385 607,263Operations and maintenance expenses215,675 207,162 49 70 126 96 215,850 207,328Income from equity method investments— — 9,495 11,242 18,530 18,666 28,025 29,908Operating income (loss) before income taxes275,587 271,697 (154) (140) (232) (203) 275,201 271,354Income before income taxes225,601 218,414 9,341 11,102 18,299 18,464 253,241 247,980Reconciliations to the condensed consolidated statements of operations and comprehensive income for the three months and nine months ended July 31, 2016 and 2015 are presented below. Three Months Nine MonthsIn thousands2016 2015 2016 2015Operating Income (Loss):       Segment operating income (loss) before income taxes$119 $(2,021) $275,201 $271,354Utility income taxes6,339 7,097 (87,660) (85,583)Regulated non-utility activities operating loss before income taxes121 89 154 140Unregulated non-utility activities operating loss before income taxes76 68 232 203Operating income $6,655$5,233 $187,927 $186,114 Net Income (Loss):       Income (loss) before income taxes for reportable segments$(11,193) $(13,260) $253,241 $247,980Income taxes4,463 5,000 (98,749) (96,860)Total$(6,730) $(8,260) $154,492 $151,120 |

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| - Definition
The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.
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