Variable Interest Entities (Details) (Variable Interest Entity, Not Primary Beneficiary [Member], USD $) In Thousands, unless otherwise specified	Jan. 31, 2015	Oct. 31, 2014
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	$ 184,478	$ 170,171
Cardinal Pipeline Company [Member]
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	15,828	16,073
Pine Needle Company [Member]
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	18,228	18,689
South Star Energy Services [Member]
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	44,080	40,965
Hardy Storage [Member]
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	37,925	37,179
Constitution Pipeline Company [Member]
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	63,489	57,255
Atlantic Coast Pipeline [Member]
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	$ 4,928	$ 10