Commitment & Contingencies (Details) (USD $)	3 Months Ended			96 Months Ended					3 Months Ended
	Jul. 31, 2013	Oct. 31, 2012	Oct. 31, 1997	Feb. 29, 2020 Tennessee Regulatory Authority [Member]	Jul. 31, 2013 Tennessee Regulatory Authority [Member]	Jul. 31, 2013 Environmental Restoration Costs [Member]	Jul. 31, 2013 Letter Of Credit [Member]	Oct. 31, 2012 Letter Of Credit [Member]	Jul. 31, 2013 Pipeline And Storage Capacity Contacts [Member] Maximum [Member]	Jul. 31, 2013 Gas Supply Contracts [Member] Maximum [Member]	Jul. 31, 2013 Telecommunications And Technology Outsourcing Contracts [Member] Maximum [Member]	Jul. 31, 2013 Hickory North Carolina Site [Member]	Jul. 31, 2013 Reidsville North Carolina Site [Member]	Jul. 31, 2013 Huntersville LNG Facility [Member]	Jul. 31, 2013 Underground Storage Tank [Member]	Jul. 31, 2013 Manufactured Gas Plant Sites [Member]	Jul. 31, 2013 Liquified Natural Gas Facilites [Member]	Jul. 31, 2013 Huntersville LNG Groundwanter Remediation [Member]
Commitments And Contingencies Disclosure [Abstract]
Number Of Regulatory Commissions	3
MGP Sites Under Settlement			9
Site Contingency Unasserted Claims	0
MGP Sites Not Under Settlement	4
Number Of Underground Storage Tanks In Operation	2
Site Contingency [Line Items]
Site Contingency Environmental Remediation Costs Recognized												$ 1,500,000	$ 600,000	$ 4,600,000
Accrual For Environmental Loss Contingencies Gross	1,600,000														300,000	1,100,000	100,000	100,000
Site Contingency Status Of Regulatory Proceedings												As part of a voluntary agreement with the NCDENR, we conducted and completed soil remediation for the Hickory, North Carolina MGP site in 2010. A Phase II groundwater investigation was conducted in 2011. A groundwater remedial action plan was submitted and approved by the NCDENR in 2012. We continue to conduct quarterly groundwater monitoring at this site in accordance with our site remediation plan.	In July 2012, the North Carolina Department of Environment and Natural Resources (NCDENR) approved our proposed groundwater investigation work plan, which included installing five monitoring wells in September 2012. The NCDENR is no longer requiring the groundwater remedial action plan.	In September 2011, we received a letter from the NCDENR indicating their desire to enter into an Administrative Consent Order (ACO) addressing the remaining groundwater issues at the site. In April 2012, we entered into a no admit/no deny ACO that imposed a fine of $40,000, unpaid annual fees totaling $18,000 and $1,860 for investigative and administrative costs. As part of the ACO, we were required to develop a site assessment plan to determine the extent of the groundwater contamination related to the sieve burial, a groundwater remediation strategy and a groundwater and surface water site-wide monitoring program. A site assessment plan was accepted by the NCDENR, and we began groundwater sampling in July 2012. We performed an initial round of sampling in our first quarter, which was inconclusive as to migration, and thus additional groundwater monitoring wells were installed during our second quarter to aid in determining the extent of the groundwater contamination. The groundwater sampling results will be submitted to the NCDENR, and based on their response, we will be required to submit additional plan(s) to remediate and/or monitor the groundwater.
Long Term Purchase Commitment [Line Items]
Long Term Purchase Commitment Time Period									22 years	15 months	3 years
Line Of Credit Facility [Line Items]
Credit Facility Amount Outstanding							2,100,000	3,600,000
Regulatory Asset [Line Items]
Regulatory Assets	258,139,000	293,104,000				10,100,000
Schedule Of Regulatory Matters [Line Items]
Approved Recovery Unamortized Environmental Costs					$ 2,000,000
Amortization Period Recovery Deferred Environmental Costs				8 years