Business Segments (Details) $ in Thousands		3 Months Ended		9 Months Ended
		Jul. 31, 2016 USD ($)	Jul. 31, 2015 USD ($)	Jul. 31, 2016 USD ($) segment	Jul. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment				3
Segment Reporting Information [Abstract]
Revenues from external customers	[1]	$ 157,806	$ 158,266	$ 969,329	$ 1,190,462
Margin		114,771	111,572	625,385	607,263
Operations and maintenance expenses		68,941	69,655	215,850	207,328
Income from equity method investments		4,238	5,801	28,025	29,908
Operating income (loss) before income taxes		119	(2,021)	275,201	271,354
Income (loss) before income taxes for reportable segments		(11,193)	(13,260)	253,241	247,980
Segment Reporting Information, Operating Income (Loss) [Abstract]
Segment operating income (loss) before income taxes		119	(2,021)	275,201	271,354
Utility income taxes		6,339	7,097	(87,660)	(85,583)
Operating income		6,655	5,233	187,927	186,114
Segment Reporting Information, Profit (Loss) [Abstract]
Income (loss) before income taxes for reportable segments		(11,193)	(13,260)	253,241	247,980
Income taxes		4,463	5,000	(98,749)	(96,860)
Net Income (Loss)		(6,730)	(8,260)	154,492	151,120
Regulated Utility
Segment Reporting Information [Abstract]
Revenues from external customers		157,806	158,266	969,329	1,190,462
Margin		114,771	111,572	625,385	607,263
Operations and maintenance expenses		68,867	69,587	215,675	207,162
Income from equity method investments		0	0	0	0
Operating income (loss) before income taxes		316	(1,864)	275,587	271,697
Income (loss) before income taxes for reportable segments		(15,233)	(18,904)	225,601	218,414
Segment Reporting Information, Operating Income (Loss) [Abstract]
Segment operating income (loss) before income taxes		316	(1,864)	275,587	271,697
Segment Reporting Information, Profit (Loss) [Abstract]
Income (loss) before income taxes for reportable segments		(15,233)	(18,904)	225,601	218,414
Regulated Non-Utility Activities
Segment Reporting Information [Abstract]
Revenues from external customers		0	0	0	0
Margin		0	0	0	0
Operations and maintenance expenses		16	19	49	70
Income from equity method investments		1,229	3,894	9,495	11,242
Operating income (loss) before income taxes		(121)	(89)	(154)	(140)
Income (loss) before income taxes for reportable segments		1,108	3,805	9,341	11,102
Segment Reporting Information, Operating Income (Loss) [Abstract]
Segment operating income (loss) before income taxes		(121)	(89)	(154)	(140)
Segment Reporting Information, Profit (Loss) [Abstract]
Income (loss) before income taxes for reportable segments		1,108	3,805	9,341	11,102
Unregulated Non-Utility Activities
Segment Reporting Information [Abstract]
Revenues from external customers		0	0	0	0
Margin		0	0	0	0
Operations and maintenance expenses		58	49	126	96
Income from equity method investments		3,009	1,907	18,530	18,666
Operating income (loss) before income taxes		(76)	(68)	(232)	(203)
Income (loss) before income taxes for reportable segments		2,932	1,839	18,299	18,464
Segment Reporting Information, Operating Income (Loss) [Abstract]
Segment operating income (loss) before income taxes		(76)	(68)	(232)	(203)
Segment Reporting Information, Profit (Loss) [Abstract]
Income (loss) before income taxes for reportable segments		$ 2,932	$ 1,839	$ 18,299	$ 18,464

[1] See Note 13 for amounts attributable to affiliates.