Regulatory Matters (Details) (USD $)	12 Months Ended											1 Months Ended			12 Months Ended						24 Months Ended	132 Months Ended						3 Months Ended	12 Months Ended					60 Months Ended			12 Months Ended		82 Months Ended	106 Months Ended	132 Months Ended	144 Months Ended				180 Months Ended	144 Months Ended		0 Months Ended	60 Months Ended			38 Months Ended			12 Months Ended												18 Months Ended			1 Months Ended		0 Months Ended	96 Months Ended		0 Months Ended	1 Months Ended	12 Months Ended	1 Months Ended			96 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2013 Deferred Pipeline Integrity Expenses [Member]	Oct. 31, 2012 Deferred Pipeline Integrity Expenses [Member]	Oct. 31, 2013 Deferred Operations And Maintenance Expenses [Member]	Oct. 31, 2012 Deferred Operations And Maintenance Expenses [Member]	Oct. 31, 2013 Environmental Restoration Costs [Member]	Oct. 31, 2012 Environmental Restoration Costs [Member]	Oct. 31, 2013 Robeson LNG Development Cost [Member]	Oct. 31, 2012 Robeson LNG Development Cost [Member]	May 31, 2013 NCUC [Member]	Oct. 31, 2013 NCUC [Member]	Oct. 31, 2012 NCUC [Member]	Dec. 31, 2014 NCUC [Member] Revenue [Member]	Oct. 31, 2013 NCUC [Member] Minimum [Member]	Oct. 31, 2013 NCUC [Member] Maximum [Member]	Oct. 31, 2013 NCUC [Member] EasternNC Exclusive Franchise Rights [Member]	Dec. 31, 2001 NCUC [Member] EasternNC Exclusive Franchise Rights [Member]	Dec. 31, 2000 NCUC [Member] EasternNC Exclusive Franchise Rights [Member]	Dec. 31, 2001 NCUC [Member] EasternNC Exclusive Franchise Rights [Member]	Dec. 31, 2008 NCUC [Member] EasternNC Exclusive Franchise Rights [Member]	Jun. 30, 2005 NCUC [Member] General Rate Case Proceeding 2005 [Member]	May 31, 2010 NCUC [Member] North Carolina Public Staff Audit 2010 Gas Cost Review Period [Member]	May 31, 2011 NCUC [Member] North Carolina Public Staff Audit 2011 Gas Cost Review Period [Member]	May 31, 2012 NCUC [Member] North Carolina Public Staff Audit 2012 Gas Cost Review Period [Member]	May 31, 2013 NCUC [Member] North Carolina Public Staff Audit 2013 Gas Cost Review Period [Member]	Dec. 31, 2013 NCUC [Member] General Rate Application Settlement 2013 [Member]	Dec. 31, 2014 NCUC [Member] General Rate Application Settlement 2013 [Member] Revenue [Member]	Dec. 31, 2014 NCUC [Member] General Rate Application Settlement 2013 [Member] Revenue [Member] Gas Utility Margin [Member]	Dec. 31, 2014 NCUC [Member] General Rate Application Settlement 2013 [Member] Revenue [Member] Fixed Gas Costs [Member]	Dec. 31, 2014 NCUC [Member] General Rate Application Settlement 2013 [Member] Operating Expense [Member]	Dec. 31, 2014 NCUC [Member] General Rate Application Settlement 2013 [Member] Revised Pre-Tax Income [Member]	Dec. 31, 2018 NCUC [Member] Deferred Pipeline Integrity Expenses [Member]	Oct. 31, 2013 NCUC [Member] Deferred Pipeline Integrity Expenses [Member]	Aug. 31, 2013 NCUC [Member] Deferred Pipeline Integrity Expenses [Member]	May 31, 2011 NCUC [Member] Deferred Pipeline Integrity Expenses [Member] General Rate Case Proceeding 2008 [Member]	Jun. 30, 2008 NCUC [Member] Deferred Pipeline Integrity Expenses [Member] General Rate Case Proceeding 2008 [Member]	Oct. 31, 2020 NCUC [Member] Deferred Operations And Maintenance Expenses [Member]	Oct. 31, 2008 NCUC [Member] Deferred Operations And Maintenance Expenses [Member]	Dec. 31, 2008 NCUC [Member] Deferred Operations And Maintenance Expenses [Member]	Oct. 31, 2020 NCUC [Member] Deferred Operations And Maintenance Expenses [Member]	Dec. 31, 2013 NCUC [Member] Deferred Operations And Maintenance Expenses [Member]	Oct. 31, 2013 NCUC [Member] Deferred Operations And Maintenance Expenses [Member]	Oct. 31, 2012 NCUC [Member] Deferred Operations And Maintenance Expenses [Member]	Oct. 31, 2020 NCUC [Member] Deferred Operations And Maintenance Expenses [Member] General Rate Case Proceeding 2005 [Member]	Oct. 31, 2020 NCUC [Member] Deferred Operations And Maintenance Expenses [Member] General Rate Case Proceeding 2008 [Member]	Oct. 31, 2008 NCUC [Member] Deferred Operations And Maintenance Expenses [Member] General Rate Case Proceeding 2008 [Member]	Aug. 31, 2013 NCUC [Member] Environmental Restoration Costs [Member] General Rate Application Settlement 2013 [Member]	Dec. 31, 2018 NCUC [Member] Environmental Restoration Costs [Member] General Rate Application Settlement 2013 [Member]	Dec. 31, 2013 NCUC [Member] Environmental Restoration Costs [Member] General Rate Application Settlement 2013 [Member]	Dec. 31, 2013 NCUC [Member] Robeson LNG Development Cost [Member]	Feb. 28, 2017 NCUC [Member] Robeson LNG Development Cost [Member] General Rate Application Settlement 2013 [Member]	Oct. 31, 2013 NCUC [Member] Robeson LNG Development Cost [Member] General Rate Application Settlement 2013 [Member]	Oct. 31, 2013 PSCSC [Member]	Oct. 31, 2013 PSCSC [Member] Minimum [Member]	Oct. 31, 2013 PSCSC [Member] Maximum [Member]	Oct. 31, 2012 PSCSC [Member] North Carolina Public Staff Audit 2011 Gas Cost Review Period [Member]	Oct. 31, 2012 PSCSC [Member] Settlement With Office Of Regulatory Staff October 2011 [Member] Margin [Member]	Oct. 31, 2012 PSCSC [Member] Settlement With Office Of Regulatory Staff October 2011 [Member] Operating Expense [Member]	Oct. 31, 2013 PSCSC [Member] Settlement With Office Of Regulatory Staff October 2012 [Member]	Oct. 31, 2013 PSCSC [Member] Settlement With Office Of Regulatory Staff October 2012 [Member] Margin [Member]	Oct. 31, 2014 PSCSC [Member] Settlement With Office Of Regulatory Staff October 2013 [Member]	Oct. 31, 2014 PSCSC [Member] Settlement With Office Of Regulatory Staff October 2013 [Member] Margin [Member]	Oct. 31, 2014 PSCSC [Member] Environmental Restoration Costs [Member] Settlement With Office Of Regulatory Staff October 2013 [Member]	Dec. 31, 2013 PSCSC [Member] Environmental Restoration Costs [Member] Settlement With Office Of Regulatory Staff October 2013 [Member]	Oct. 31, 2013 PSCSC [Member] Robeson LNG Development Cost [Member]	Jun. 30, 2010 Tennessee Regulatory Authority [Member]	Oct. 31, 2013 Tennessee Regulatory Authority [Member]	Feb. 29, 2012 Tennessee Regulatory Authority [Member]	May 31, 2012 Tennessee Regulatory Authority [Member] Collection Nashville Franchise Fee [Member]	Oct. 31, 2011 Tennessee Regulatory Authority [Member] Collection Nashville Franchise Fee [Member]	Mar. 01, 2012 Tennessee Regulatory Authority [Member] General Rate Application Settlement 2012 [Member]	Feb. 29, 2020 Tennessee Regulatory Authority [Member] General Rate Application Settlement 2012 [Member]	Oct. 31, 2010 Tennessee Regulatory Authority [Member] General Rate Application Settlement 2012 [Member]	Mar. 01, 2012 Tennessee Regulatory Authority [Member] General Rate Application Settlement 2012 [Member] Revenue [Member]	Sep. 30, 2011 Tennessee Regulatory Authority [Member] General Rate Application Settlement 2012 [Member] Revenue [Member]	Oct. 31, 2013 Tennessee Regulatory Authority [Member] General Rate Application Settlement 2012 [Member] Revenue [Member]	Aug. 31, 2013 Tennessee Regulatory Authority [Member] Requested Adjustment Filed August 2013 [Member]	Feb. 28, 2010 Tennessee Regulatory Authority [Member] Franchise Fees [Member] Collection Nashville Franchise Fee [Member]	Oct. 31, 2011 Tennessee Regulatory Authority [Member] Franchise Fees [Member] Collection Nashville Franchise Fee [Member]	Feb. 29, 2020 Tennessee Regulatory Authority [Member] Environmental Restoration Costs [Member] General Rate Application Settlement 2012 [Member]	Mar. 31, 2012 Tennessee Regulatory Authority [Member] Environmental Restoration Costs [Member] General Rate Application Settlement 2012 [Member]
Public Utilities Rate Matters Approved [Abstract]
Public Utilities Approved Rate Increase (Decrease) Amount																													$ 30,700,000	$ 16,800,000	$ 13,800,000	$ (10,900,000)	$ 24,200,000																										$ (3,100,000)	$ (1,900,000)		$ (1,100,000)		$ (100,000)												$ 11,900,000
Public Utilities Approved Rate Increase (Decrease) Percentage															3.58%																																																													6.30%
Public Utilities Approved Return On Equity Percentage																												10.00%																														11.30%			11.30%		11.30%										10.20%
Public Utilities, Approved Equity Capital Structure, Percentage																												50.70%
Approved Annual Average Revenue Percentage Increase From Last Rate Case																												0.70%
Denied Franchise Fees																																																																																	1,500,000
Operations And Maintenence Expense Maximum Deferral																																									15,000,000
Deferral Time Period Of Operation And Maintenance Expense																																									8 years
Amortization Time Period For Specified Expenses																																		5 years			3 years		82 months							15 years	12 years		5 years	5 years			38 months										1 year		1 year									8 years								8 years
Overall Rate Base With Approved Rates And Charges																												1,800,000,000
Public Utilities Rate Matters Requested [Abstract]
Public Utilities Requested Rate Increase (Decrease) Amount												79,800,000																																																																	16,700,000		13,100,000	2,900,000
Public Utilities Requested Rate Increase (Decrease) Percentage												9.30%																																																																		8.90%
Request Transfer Plant Held For Future Use To Deferred Regulatory Asset														6,700,000
Requested Adjustment Deferred Gas Costs																																																																															3,700,000
Regulatory Assets	246,306,000	293,104,000		19,449,000	13,691,000	6,376,000	7,050,000	9,416,000	10,202,000	1,808,000	0												7,900,000												19,449,000	17,300,000		4,600,000					6,300,000	6,376,000	7,050,000			9,000,000			6,300,000	1,200,000		1,200,000											200,000	200,000	500,000								1,000,000								2,000,000
Public Utilities Description Of Regulatory Scope	Our utility operations are regulated by the NCUC, PSCSC and TRA as to rates, service area, adequacy of service, safety standards, extensions and abandonment of facilities, accounting and depreciation. We are also regulated by the NCUC as to the issuance of long-term debt and equity securities. The NCUC and the PSCSC regulate our gas purchasing practices under a standard of prudence and audit our gas cost accounting practices. The TRA regulates our gas purchasing practices under a gas supply incentive program which compares our actual costs to market pricing benchmarks. As part of this jurisdictional oversight, all three regulatory commissions address our gas supply hedging activities. Additionally, all three regulatory commissions allow for recovery of uncollectible gas costs through the PGA. The portion of uncollectibles related to gas costs is recovered through the deferred account and only the non-gas costs, or margin, portion of uncollectibles is included in base rates and uncollectibles expense. Our three regulatory commissions have authorized us to utilize deferral accounting in connection with environmental costs.
Maximum Utility Rate Of Return Change Under RSA																																																							50
Target Percentage Range Normalized Sales																22.5%	45.0%																																							22.5%	45.0%
North Carolina General Assembly Bond Issuance Amount																			149,600,000	38,700,000	188,300,000	200,000,000
Operational Feasibility Assessment Time Period																		2 years
Interest Accrued On Deferred Expenses																																							6.55%	8.69%		7.84%
Percentage Of Allowed Recovery For Gas Costs																								100.00%	100.00%	100.00%	100.00%
Percentage Of Net Secondary Market Margins Flowed Through To Customers													75.00%																																										75.00%														75.00%
Percentage Of Net Secondary Market Margins Retained													25.00%																																										25.00%														25.00%
Annual Incentive Cap On Gains And Losses																																																																					1,600,000
Operations and maintenance	253,120,000	242,599,000	225,351,000																																																																				500,000	1,500,000
Audit Period To Synchronize Audit Year																																																																				18 months
Total Amount Of Margin Generated From Secondary Market Activity	35,900,000	38,700,000	56,100,000
Amount Of Net Secondary Market Margins Flowed Through To Jurisdictional Customers	26,900,000	29,000,000	42,100,000
Amount Of Net Secondary Market Margins Retained	$ 9,000,000	$ 9,700,000	$ 14,000,000
Recovery Of Fixed Charges Cost Allocations																																																																						29.00%			37.00%
Recovery Of Volumetric Charges Cost Allocations																																																																						71.00%			63.00%