Variable Interest Entities (Details) (USD $)	Oct. 31, 2011	Oct. 31, 2010
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	$ 85,121,000	$ 80,287,000
Cardinal Pipeline Company [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	18,323,000	11,837,000
Pine Needle Company [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	18,690,000	21,810,000
South Star Energy Services [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	17,536,000	17,146,000
Piedmont Hardy Storage [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	$ 30,572,000	$ 29,494,000