Variable Interest Entities (Details) (Variable Interest Entity, Not Primary Beneficiary [Member], USD $) In Thousands, unless otherwise specified	Jul. 31, 2014	Oct. 31, 2013
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	$ 163,473	$ 128,469
Cardinal Pipeline Company [Member]
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	16,275	18,207
Pine Needle Company [Member]
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	19,057	20,270
South Star Energy Services [Member]
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	41,368	38,372
Hardy Storage [Member]
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	36,382	34,681
Constitution Pipeline Company [Member]
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	$ 50,391	$ 16,939