Piedmont Natural Gas (PNY) 10-Q 5 Jun 15 2015 Q2 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	6 Months Ended
	Apr. 30, 2015	Jun. 01, 2015
Document And Entity Information [Abstract]
Entity Registrant Name	PIEDMONT NATURAL GAS CO INC
Entity Central Index Key	78460
Document Type	10-Q
Document Period End Date	30-Apr-15
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2015
Amendment Flag	FALSE
Current Fiscal Year End Date	-21
Entity Filer Category	Large Accelerated Filer
Entity Common Stock Shares Outstanding		78,995,201
Trading Symbol	PNY

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (Unaudited) (USD $)	Apr. 30, 2015		Oct. 31, 2014
In Thousands, unless otherwise specified
Utility Plant:
Utility plant in service	$5,171,273		$5,011,497
Less accumulated depreciation	1,218,369		1,166,922
Utility plant in service, net	3,952,904		3,844,575
Construction work in progress	180,054		141,693
Plant held for future use	3,155		3,155
Total utility plant, net	4,136,113		3,989,423
Other Physical Property, at cost (net of accumulated depreciation of $915 in 2015 and $904 in 2014	343		355
Current Assets:
Cash and cash equivalents	13,382		9,643
Trade accounts receivable(1) (less allowance for doubtful accounts of $5,158 in 2015 and $2,152 in 2014)	82,942	[1]	65,260	[1]
Income taxes receivable	9,499		36,100
Other receivables	8,417		3,361
Unbilled utility revenues	13,520		21,093
Inventories:
Gas in storage	54,371		84,081
Materials, supplies and merchandise	1,681		1,652
Gas purchase derivative assets, at fair value	2,142		4,898
Regulatory assets	11,537		29,088
Prepayments	18,872		39,030
Deferred income taxes	13,095		53,418
Other current assets	354		326
Total current assets	229,812		347,950
Noncurrent Assets:
Equity method investments in non-utility activities	185,991		170,171
Goodwill	48,852		48,852
Regulatory assets	181,440		184,779
Income taxes receivable	25,875		0
Marketable securities, at fair value	4,705		3,727
Overfunded postretirement asset	43,557		33,757
Other noncurrent assets	4,684		5,239
Total noncurrent assets	495,104		446,525
Total	4,861,372		4,784,253
Stockholders’ equity:
Cumulative preferred stock – no par value – 175 shares authorized	0		0
Common stock - no par value - shares authorized: 200,000 shares; outstanding: 78,983 in 2015 and 78,531 in 2014	653,252		636,835
Retained earnings	780,278		672,004
Accumulated other comprehensive loss	-970		-237
Total stockholders’ equity	1,432,560		1,308,602
Long-term debt	1,424,443		1,424,430
Total capitalization	2,857,003		2,733,032
Current Liabilities:
Short-term debt	255,000		355,000
Trade accounts payable (1)	75,817	[1]	85,299	[1]
Other accounts payable	43,233		54,349
Accrued interest	28,684		27,982
Customers’ deposits	21,993		19,994
General taxes accrued	13,561		23,828
Regulatory liabilities	61,498		46,231
Other current liabilities	7,255		9,303
Total current liabilities	507,041		621,986
Noncurrent Liabilities:
Deferred income taxes	865,042		809,467
Unamortized federal investment tax credits	1,107		1,193
Accumulated provision for postretirement benefits	15,448		15,471
Regulatory liabilities	569,913		558,598
Conditional cost of removal obligations	15,127		14,647
Other noncurrent liabilities	30,691		29,859
Total noncurrent liabilities	1,497,328		1,429,235
Commitments and Contingencies
Total	$4,861,372		$4,784,253
[1]	See Note 12 for amounts attributable to affiliates.

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Unaudited) (Parentheticals) (USD $)	Apr. 30, 2015	Oct. 31, 2014
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Other Physical Property accumulated depreciation	$915	$904
Allowance for doubtful accounts	$5,158	$2,152
Cumulative preferred stock par value	$0	$0
Cumulative preferred stock shares authorized	175,000	175,000
Common stock par value per share	$0	$0
Common stock shares authorized	200,000,000	200,000,000
Common stock shares outstanding	78,983,000	78,531,000

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $)	3 Months Ended				6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Apr. 30, 2015		Apr. 30, 2014		Apr. 30, 2015	Apr. 30, 2014
Statement of Comprehensive Income [Abstract]
Operating Revenues (1)	$424,924	[1]	$462,247	[1]	$1,032,196	$1,119,980
Cost of Gas (1)	199,303	[1]	250,724	[1]	536,505	646,945
Margin	225,621		211,523		495,691	473,035
Operating Expenses:
Operations and maintenance	71,424		70,193		137,574	130,832
Depreciation	31,689		28,344		63,583	57,987
General taxes	10,976		9,497		20,972	18,606
Utility income taxes	36,409		36,190		92,680	95,992
Total operating expenses	150,498		144,224		314,809	303,417
Operating Income	75,123		67,299		180,882	169,618
Other Income (Expense):
Income from equity method investments	15,842		14,360		24,107	24,302
Non-operating income	631		-1,045		1,261	-795
Non-operating expense	-1,197		-1,443		-1,897	-2,052
Income taxes	-5,916		-4,604		-9,180	-8,332
Total other income (expense)	9,360		7,268		14,291	13,123
Utility Interest Charges:
Interest on long-term debt	17,460		14,902		34,950	30,495
Allowance for borrowed funds used during construction	-2,804		-5,464		-5,076	-11,416
Other	3,425		2,589		5,919	3,550
Total utility interest charges	18,081		12,027		35,793	22,629
Net Income	66,402		62,540		159,380	160,112
Other Comprehensive Income (Loss), net of tax:
Unrealized gain (loss) from hedging activities of equity method investments, net of tax of ($201) and $224 for the three months ended April 30, 2015 and 2014, respectively, and ($801) and $335 for the six months ended April 30, 2015 and 2014, respectively	-316		352		-1,260	526
Reclassification adjustment of realized gain (loss) from hedging activities of equity method investments included in net income, net of tax of $286 and ($228) for the three months ended April 30, 2015 and 2014, respectively, and $361 and ($140) for the six months ended April 30, 2015 and 2014, respectively	449		-359		566	-222
Net current period benefit activities of equity method investments, net of tax of ($25) for the three months ended April 30, 2015 and ($25) for the six months ended April 30, 2015	-39				-39
Total other comprehensive income (loss)	94		-7		-733	304
Comprehensive Income	$66,496		$62,533		$158,647	$160,416
Average Shares of Common Stock:
Basic (in shares)	78,818		77,982		78,717	77,477
Diluted (in shares)	79,115		78,291		79,048	77,802
Earnings Per Share of Common Stock:
Basic (usd per share)	$0.84		$0.80		$2.02	$2.07
Diluted (usd per share)	$0.84		$0.80		$2.02	$2.06
[1]	See Note 12 for amounts attributable to affiliates.

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (Parentheticals) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2015	Apr. 30, 2014
Statement of Comprehensive Income [Abstract]
Unrealized gain (loss) from hedging activities of equity method investments arising during period tax	($201)	$224	($801)	$335
Reclassification adjustment of realized gain (loss) from hedging activities of equity investments included in net income, tax	286	-228	361	-140
Net current period benefit activities of equity method investments, tax	($25)		($25)

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2015	Apr. 30, 2014
Cash Flows from Operating Activities:
Net income	$159,380	$160,112
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	69,320	62,864
Allowance for doubtful accounts	3,006	3,280
Income from equity method investments	-24,107	-24,302
Distributions of earnings from equity method investments	21,465	15,880
Deferred income taxes, net	96,277	85,982
Changes in assets and liabilities:
Gas purchase derivatives, at fair value	2,756	-167
Receivables	-18,078	-74,433
Inventories	29,681	24,214
Settlement of legal asset retirement obligations	-2,225	-1,391
Regulatory assets	15,553	47,553
Other assets	24,472	26,446
Accounts payable	-16,535	-5,043
Provision for postretirement benefits, net	-9,823	-20,069
Regulatory liabilities	17,987	78,791
Other liabilities	-4,796	3,049
Net cash provided by operating activities	364,333	382,766
Cash Flows from Investing Activities:
Utility capital expenditures	-204,336	-236,850
Allowance for borrowed funds used during construction	-5,076	-11,416
Contributions to equity method investments	-15,495	-18,600
Distributions of capital from equity method investments	1,119	8,533
Proceeds from sale of property	357	712
Investments in marketable securities	-838	-534
Other	2,311	1,142
Net cash used in investing activities	-221,958	-257,013
Cash Flows from Financing Activities:
Net repayments – commercial paper	-100,000	-30,000
Repayment of long-term debt	0	-100,000
Expenses related to issuance of debt	-1	-492
Proceeds from issuance of common stock, net of expenses	0	47,290
Issuance of common stock through dividend reinvestment and employee stock plans	12,886	12,263
Dividends paid	-51,169	-49,064
Other	-352	34
Net cash used in financing activities	-138,636	-119,969
Net Increase in Cash and Cash Equivalents	3,739	5,784
Cash and Cash Equivalents at Beginning of Period	9,643	8,063
Cash and Cash Equivalents at End of Period	13,382	13,847
Cash Paid During the Period for:
Interest	35,492	33,311
Income Taxes:
Income taxes paid	1,978	4,381
Income taxes refunded	530	19
Income taxes, net	1,448	4,362
Noncash Investing and Financing Activities:
Accrued capital expenditures	$34,772	$36,930

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (USD $)	Total	Common Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
In Thousands, unless otherwise specified
Stockholders' Equity, beginning balance at Oct. 31, 2013	$1,188,596	$561,644	$627,236	($284)
Common Stock, Shares, Outstanding, Beginning Balance at Oct. 31, 2013		76,099
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	160,112		160,112
Other Comprehensive Income (Loss)	304			304
Common Stock Issued	61,687	61,687
Common Stock Issued (Shares)		2,039
Expenses from Issuance of Common Stock	-12	-12
Tax Benefit from Dividends Paid on ESOP Shares	58		58
Dividends Declared	49,064		49,064
Stockholders' Equity, ending balance at Apr. 30, 2014	1,361,681	623,319	738,342	20
Common Stock, Shares, Outstanding, Ending Balance at Apr. 30, 2014		78,138
Stockholders' Equity, beginning balance at Oct. 31, 2014	1,308,602	636,835	672,004	-237
Common Stock, Shares, Outstanding, Beginning Balance at Oct. 31, 2014	78,531	78,531
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	159,380		159,380
Other Comprehensive Income (Loss)	-733			-733
Common Stock Issued	16,775	16,775
Common Stock Issued (Shares)		452
Expenses from Issuance of Common Stock	-358	-358
Tax Benefit from Dividends Paid on ESOP Shares	63		63
Dividends Declared	51,169		51,169
Stockholders' Equity, ending balance at Apr. 30, 2015	$1,432,560	$653,252	$780,278	($970)
Common Stock, Shares, Outstanding, Ending Balance at Apr. 30, 2015	78,983	78,983

Condensed_Consolidated_Stateme4

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parentheticals) (USD $)	6 Months Ended
	Apr. 30, 2015	Apr. 30, 2014
Statement of Stockholders' Equity [Abstract]
Dividends declared per share	$0.65	$0.63

Summary_of_Significant_Account

Summary of Significant Accounting Policies	6 Months Ended
	Apr. 30, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies
	Unaudited Interim Financial Information
	The condensed consolidated financial statements have not been audited. We have prepared the unaudited condensed consolidated financial statements under the rules of the Securities and Exchange Commission (SEC). Therefore, certain financial information and note disclosures normally included in annual financial statements prepared in conformity with generally accepted accounting principles (GAAP) in the United States of America are omitted in this interim report under these SEC rules and regulations. These financial statements should be read in conjunction with the Consolidated Financial Statements and Notes included in our Form 10-K for the year ended October 31, 2014.
	Seasonality and Use of Estimates
	The unaudited condensed consolidated financial statements include all normal recurring adjustments necessary for a fair presentation of the statement of financial position at April 30, 2015 and October 31, 2014, the results of operations for three months and six months ended April 30, 2015 and 2014, and cash flows and stockholders’ equity for the six months ended April 30, 2015 and 2014. Our business is seasonal in nature. The results of operations for the three months and six months ended April 30, 2015 do not necessarily reflect the results to be expected for the full year.
	In accordance with GAAP, we make certain estimates and assumptions regarding reported amounts of assets, liabilities, revenues and expenses and the related disclosures, using historical experience and other assumptions that we believe are reasonable at the time. Our estimates may involve complex situations requiring a high degree of judgment in the application and interpretation of existing literature or in the development of estimates that impact our financial statements. These estimates and assumptions affect the reported amounts of assets and liabilities as of the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates and assumptions, which are evaluated on a continual basis.
	Significant Accounting Policies
	Our accounting policies are described in Note 1 to the consolidated financial statements in our Form 10-K for the year ended October 31, 2014. There were no significant changes to those accounting policies during the six months ended April 30, 2015.
	Rate-Regulated Basis of Accounting
	Our utility operations are subject to regulation with respect to rates, service area, accounting and various other matters by the regulatory commissions in the states in which we operate. The accounting regulations provide that rate-regulated public utilities account for and report assets and liabilities consistent with the economic effect of the manner in which independent third-party regulators establish rates. In applying these regulations, we capitalize certain costs and benefits as regulatory assets and liabilities, respectively, in order to provide for recovery from or refund to utility customers in future periods. Generally, regulatory assets are amortized to expense and regulatory liabilities are amortized to income over the period authorized by our regulators.
	Our regulatory assets are recoverable through either base rates or rate riders specifically authorized by a state regulatory commission. Base rates are designed to provide both a recovery of cost and a return on investment during the period the rates are in effect. As such, all of our regulatory assets are subject to review by the respective state regulatory commissions during any future rate proceedings. In the event that accounting for the effects of regulation were no longer applicable, we would recognize a write-off of the regulatory assets and regulatory liabilities that would result in an adjustment to net income or accumulated other comprehensive income (loss) (OCIL). Our utility operations continue to recover their costs through cost-based rates established by the state regulatory commissions. As a result, we believe that the accounting prescribed under rate-based regulation remains appropriate. It is our opinion that all regulatory assets are recoverable in current rates or in future rate proceedings. Our regulatory assets and liabilities are detailed in Note 2 to the condensed consolidated financial statements in this Form 10-Q.
	Fair Value Measurements
	We have financial and nonfinancial assets and liabilities subject to fair value measurement. The financial assets and liabilities measured and carried at fair value in the Condensed Consolidated Balance Sheets are cash and cash equivalents, marketable securities held in rabbi trusts established for our deferred compensation plans and derivative assets and liabilities, if any, that are held for our utility operations. The carrying values of receivables, short-term debt, accounts payable, accrued interest and other current assets and liabilities approximate fair value as all amounts reported are to be collected or paid within one year. Our nonfinancial assets and liabilities include our qualified pension and postretirement plan assets and liabilities that are recorded at fair value in the Condensed Consolidated Balance Sheets in accordance with employers’ accounting and related disclosures of postretirement plans.
	Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date, or exit date. We utilize market data or assumptions that market participants would use in valuing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, market corroborated or generally unobservable. We primarily apply the market approach for fair value measurements and endeavor to utilize the best available information. Accordingly, we use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. The fair value of our financial assets and liabilities are subject to potentially significant volatility based on changes in market prices, the portfolio valuation of our contracts, as well as the maturity and settlement of those contracts, and subsequent newly originated transactions, each of which directly affects the estimated fair value of our financial instruments. We are able to classify fair value balances based on the observance of those inputs at the lowest level that is significant to the fair value measurement, in its entirety, in the fair value hierarchy levels as set forth in the fair value guidance.
	For the fair value measurements of our derivatives and marketable securities, see Note 8 to the condensed consolidated financial statements in this Form 10-Q. For the fair value measurements of our benefit plan assets, see Note 9 to the consolidated financial statements in our Form 10-K for the year ended October 31, 2014. For further information on our fair value methodologies, see “Fair Value Measurements” in Note 1 to the consolidated financial statements in our Form 10-K for the year ended October 31, 2014. There were no significant changes to these fair value methodologies during the three months ended April 30, 2015.
	Recently Issued Accounting Guidance
	Guidance	Description	Effective date	Effect on the financial statements or other significant matters
	ASU 2014-09, May 2014, Revenue from Contracts with Customers (Topic 606)	Under the new standard, entities will recognize revenue to depict the transfer of goods and services to customers in amounts that reflect the payment to which the entity expects to be entitled in exchange for those goods or services. The disclosure requirements will provide information about the nature, amount, timing and uncertainty of revenue and cash flows from an entity’s contracts with customers.	Annual periods beginning after December 15, 2016, and interim periods within those periods.	We have been evaluating the effect on our financial position, results of operations and cash flows. The evaluation includes identifying revenue streams by like contracts to allow for ease of implementation. In our evaluation, we are following the efforts of an accounting utility subgroup and its issuance of a revenue implementation guide.
			The Financial Accounting Standards Board (FASB) proposed the deferral of the effective date to annual periods beginning after December 15, 2017 (beginning November 1, 2018 for us) and interim periods within that period, with early adoption permitted for annual periods beginning after December 15, 2016.
	ASU 2014-15, August 2014, Presentation of Financial Statements - Going Concern (Subtopic 205-40)	The FASB issued accounting guidance on determining when and how reporting entities must disclose going concern uncertainties in their financial statements. The new standard requires management to perform interim and annual assessments of an entity's ability to continue as a going concern within one year of the date of issuance of the entity's financial statements. An entity must provide certain disclosures if there is a "substantial doubt about the entity's ability to continue as a going concern."	Annual periods ending after December 15, 2016 (October 31, 2017 for us), and interim and annual periods thereafter; early adoption is permitted.	The adoption of this guidance will have no impact on our financial position, results of operations or cash flows. It will require establishing a going concern assessment process to meet the standard.
	ASU 2015-01, January 2015, Income Statement - Extraordinary and Unusual Items (Subtopic 225-20)	The FASB issued accounting guidance eliminating the concept of extraordinary items, thus eliminating the need to assess whether a particular event or transaction event is extraordinary. The presentation and disclosure guidance for items that are unusual in nature or occur infrequently will be retained and will be expanded to include items that are both unusual in nature and infrequently occurring, with the amendments being applicable either prospectively or retrospectively, to all prior periods presented in the financial statements.	Annual periods beginning after December 15, 2015 (November 1, 2016 for us), and interim periods within those periods, with early adoption permitted, provided that the guidance is applied from the beginning of the fiscal year of adoption.	The adoption of this guidance will be applied on a prospective basis. We have not had any extraordinary or unusual items that would impact our financial position, results of operations or cash flows.
	ASU 2015-02, February 2015, Consolidation - Amendments to the Consolidation Analysis (Topic 810)	The FASB issued accounting guidance which amends the consolidation requirements in ASC 810. The amendments significantly changes the consolidation analysis required under U.S. GAAP. The focus of this guidance is largely on the investment management industry related to limited partnerships becoming variable interest entities; however, it could have an impact on the consolidation conclusions of reporting entities in other industries.	Annual periods beginning after December 15, 2015 (November 1, 2016 for us), and interim periods within those periods, with early adoption permitted, provided that the guidance is applied from the beginning of the annual period containing the adoption date.	The adoption of this guidance will have no impact on our financial position, results of operations or cash flows.
	ASU 2015-03, April 2015, Interest: Imputation of Interest - Simplifying the Presentation of Debt Issuance Costs(Subtopic 835-30)	The FASB issued accounting guidance as part of its simplification initiative to reduce complexity in accounting standards. The amendment requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by this amendment.	Annual periods beginning after December 15, 2015 (November 1, 2016 for us), and interim periods within those fiscal years, with early adoption permitted for financial statements that have not been previously issued.	The adoption of this guidance will have no effect on the results of operations or cash flows. It will retrospectively affect the presentation of the balance sheet line items current and noncurrent "Regulatory assets," "Long-term debt" and "Short-term debt."
	ASU 2015-05, April 2015, Intangibles -Goodwill and Other - Internal-Use Software: Customer's Accounting for Fees Paid in a Cloud Computing Arrangement (Subtopic 350-40)	The FASB issued accounting guidance that amends ASC 350-40 to provide customers with guidance on determining whether a cloud computing arrangement contains a software license that should be accounted for as internal-use software. The guidance applies only to hosting arrangements if both of the following criteria are met: (a) the customer has the contractual right to take possession of the software at any time during the hosting period without significant penalty and (b) it is feasible for the customer to run the software on its own hardware or contract with another party to host the software.	Annual periods (and interim periods therein) beginning after December 15, 2015 (November 1, 2016 for us), with early adoption permitted. Entities may adopt the guidance (1) retrospectively or (2) prospectively to arrangements entered into, or materially modified, after the effective date.	We are currently evaluating the effect on our financial position, results of operations and cash flows.
	ASU 2015-07, May 2015, Fair Value Measurement: Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent) (Topic 820)	The FASB issued accounting guidance that amends the required disclosure of	Annual periods beginning after December 15, 2015 (November 1, 2016 for us), and interim periods within those fiscal years, with retrospective application to all periods presented and early adoption permitted.	The adoption of this guidance will have no impact on our financial position, results of operations or cash flows. We will present certain benefit plan assets under the new guidance.
		investments for which fair value is measured at net asset value per share (or its equivalent). The amendments remove the requirement to make certain disclosures for all investments that are eligible to be measured at fair value using the net asset value per share practical expedient.

Regulatory_Matters

Regulatory Matters	6 Months Ended
	Apr. 30, 2015
Public Utilities, General Disclosures [Abstract]
Regulatory Matters	Regulatory Matters
	Regulatory assets and liabilities in the Condensed Consolidated Balance Sheets as of April 30, 2015 and October 31, 2014 are as follows.
	In thousands	April 30,		October 31,
		2015		2014
	Regulatory Assets:
	Current:
	Unamortized debt expense	$	1,516	$	1,490
	Amounts due from customers	—		16,108
	Environmental costs	1,541		1,568
	Deferred operations and maintenance expenses	916		916
	Deferred pipeline integrity expenses	3,470		3,470
	Deferred pension and other retirement benefit costs	2,757		2,769
	Robeson liquefied natural gas (LNG) development costs	649		917
	Other	688		1,850
	Total current	11,537		29,088
	Noncurrent:
	Unamortized debt expense	14,632		15,402
	Environmental costs	5,735		6,470
	Deferred operations and maintenance expenses	4,331		4,721
	Deferred pipeline integrity expenses	26,024		24,694
	Deferred pension and other retirement benefit costs	19,239		18,799
	Amounts not yet recognized as a component of pension and other retirement benefit costs	91,088		94,265
	Regulatory cost of removal asset	18,649		18,275
	Robeson LNG development costs	318		509
	Other	1,424		1,644
	Total noncurrent	181,440		184,779
	Total	$	192,977	$	213,867
	Regulatory Liabilities:
	Current:
	Amounts due to customers	$	61,498	$	46,231
	Noncurrent:
	Regulatory cost of removal obligations	515,168		506,574
	Deferred income taxes	54,656		51,930
	Amounts not yet recognized as a component of pension and other retirement benefit costs	89		94
	Total noncurrent	569,913		558,598
	Total	$	631,411	$	604,829
	Rate and Regulatory Actions
	North Carolina
	In December 2014, we filed a petition with the North Carolina Utilities Commission (NCUC) seeking authority to collect through adjusted rates an additional $26.6 million in annual integrity management rider (IMR) margin revenues effective February 2015 based on $241.9 million of capital investments in integrity and safety projects over the twelve-month period ended October 31, 2014. In January 2015, the NCUC issued an order authorizing the requested IMR rate adjustments, subject to further review and determination of the reasonableness and prudence of the capital investments and associated costs reflected in the adjustments in our annual IMR adjustment proceedings or next general rate case, with any adjustments to be implemented through a prospective rate adjustment at or after the time such adjustment is approved by the NCUC. We are currently in discussion with the North Carolina Public Staff to jointly develop a procedural schedule for the annual IMR audit/rate approval process.
	In March 2015, we filed a petition with the NCUC seeking authority for a one-time gas cost bill credit, including applicable sales taxes, for our retail sales and transportation customers in North Carolina. In March 2015, the NCUC issued an order approving our request. The bill credit of approximately $45 million was reflected on customers' April bills, reducing amounts due to customers in North Carolina.
	South Carolina
	In June 2015, we filed testimony with the Public Service Commission of South Carolina (PSCSC) in support of our annual review of purchased gas adjustment and gas purchasing policies for the twelve months ended March 31, 2015. A hearing is scheduled for July 8, 2015.
	Tennessee
	In February 2014, we filed a petition with the Tennessee Regulatory Authority (TRA) to authorize us to amortize and refund $4.7 million to customers for recorded excess deferred taxes. We proposed to refund this amount to customers over three years. We are waiting on a ruling from the TRA at this time.
	In August 2014, we filed an annual report with the TRA reflecting the shared gas cost savings from gains and losses derived from gas purchase benchmarking and secondary market transactions for the twelve months ended June 30, 2014 under the Tennessee Incentive Plan (TIP). In March 2015, the TRA Utilities Division Audit Staff (Audit Staff) submitted their report on the TIP with which we concurred. In April 2015, the TRA approved and adopted the Audit Staff's report and issued their written order in May 2015.
	In September 2014, we filed a petition with the TRA seeking authority to implement a compressed natural gas (CNG) infrastructure rider to recover the costs of our capital investments in infrastructure and equipment associated with this alternative motor vehicle transportation fuel. We proposed that the tariff rider be effective October 1, 2014 with an initial rate adjustment on November 1, 2014 based on capital expenditures incurred through June 2014 and for rates to be updated annually outside of general rate cases for the return of and on these capital investments. In November 2014, the TRA consolidated this docket with a separate petition we filed seeking modifications to our tariff regarding service to customers using natural gas as a motor fuel. A hearing on this matter was held in January 2015. In February 2015, the TRA (1) denied approval of the proposed tariff rider, (2) ruled that our retail CNG motor fuel service should be unregulated and no longer provided under our regulated tariff, and (3) approved the proposed modification to our tariff providing natural gas for motor fuel purposes at customer premises. The TRA indicated that we may seek recovery of our prior investments in CNG equipment of $4.7 million since our last rate proceeding in utility rate base in our next general rate case proceeding as the investments were made in good faith under the assumption retail CNG motor fuel would be a regulated service. We are waiting on the TRA's written order.
	In December 2014, we filed a petition with the TRA seeking authority to collect through adjusted rates an additional $6.5 million in annual IMR margin revenues effective January 2015 based on $54 million of capital investments in integrity and safety projects over the twelve-month period ended October 31, 2014. In January 2015, the TRA accepted and approved the requested IMR rate adjustment and issued its written order in February 2015.
	In December 2014, we filed an annual report for the twelve months ended June 30, 2013 with the TRA reflecting the transactions in the deferred gas cost account for the Actual Cost Adjustment mechanism. We are waiting on a ruling from the TRA at this time.

Earnings_Per_Share

Earnings Per Share	6 Months Ended
	Apr. 30, 2015
Earnings Per Share [Abstract]
Earnings Per Share	Earnings per Share
	We compute basic earnings per share (EPS) using the daily weighted average number of shares of common stock outstanding during each period. In the calculation of fully diluted EPS, shares of common stock to be issued under approved incentive compensation plans and forward sale agreements (FSAs) are contingently issuable shares, as determined by applying the treasury stock method, and are added to average common shares outstanding, resulting in a potential reduction in diluted EPS.
	A reconciliation of basic and diluted EPS, which includes contingently issuable shares that could affect EPS if performance units ultimately vest and the FSA settles in shares, for the three months and six months ended April 30, 2015 and 2014 is presented below.
		Three Months				Six Months
	In thousands, except per share amounts	2015		2014		2015		2014
	Net Income	$	66,402	$	62,540	$	159,380	$	160,112
	Average shares of common stock outstanding for basic earnings per share	78,818		77,982		78,717		77,477
	Contingently issuable shares under incentive compensation plans	279		309		302		325
	Contingently issuable shares under forward sale agreement	18				29
	Average shares of dilutive stock	79,115		78,291		79,048		77,802
	Earnings Per Share of Common Stock:
	Basic	$	0.84	$	0.8	$	2.02	$	2.07
	Diluted	$	0.84	$	0.8	$	2.02	$	2.06

Long_Term_Debt_Instruments

Long Term Debt Instruments	6 Months Ended
	Apr. 30, 2015
Long-term Debt, Unclassified [Abstract]
Long-term Debt [Text Block]	Long-Term Debt Instruments
	In June 2014, we filed a combined debt and equity shelf registration statement with the SEC that became effective on June 6, 2014. The NCUC has approved debt and equity issuances under this shelf registration statement up to $1 billion during its three-year life. As of April 30, 2015, before settlement of the FSA expected in October 2015, we have $750 million remaining for debt and equity issuances as approved by the NCUC. For further information on equity transactions, see Note 6 to the condensed consolidated financial statements in this Form 10-Q. Unless otherwise specified at the time such securities are offered for sale, the net proceeds from the sale of the securities will be used to finance capital expenditures, to repay outstanding short-term, unsecured notes under our commercial paper (CP) program, to refinance other indebtedness, to repurchase our common stock, to pay dividends and for general corporate purposes.
	We are subject to default provisions related to our long-term debt and short-term borrowings. Failure to satisfy any of the default provisions may result in total outstanding issues of debt becoming due. There are cross default provisions in all of our debt agreements.

Short_Term_Debt_Instruments

Short Term Debt Instruments	6 Months Ended
	Apr. 30, 2015
Line of Credit Facility [Abstract]
Short-Term Debt Instruments	Short-Term Debt Instruments
	We have an $850 million five-year revolving syndicated credit facility that expires on October 1, 2017. We pay an annual fee of $35,000 plus 8.5 basis points for any unused amount. The facility provides a line of credit for letters of credit of $10 million of which $1.7 million and $1.8 million were issued and outstanding as of April 30, 2015 and October 31, 2014, respectively. These letters of credit are used to guarantee claims from self-insurance under our general and automobile liability policies. The credit facility bears interest based on the 30-day London Interbank Offered Rate (LIBOR) plus from 75 to 125 basis points, based on our credit ratings. Amounts borrowed are continuously renewable until the expiration of the facility in 2017, provided that we are in compliance with all terms of the agreement.
	We have an $850 million unsecured CP program that is backstopped by the revolving syndicated credit facility. The amounts outstanding under the revolving syndicated credit facility and the CP program, either individually or in the aggregate, cannot exceed $850 million. The notes issued under the CP program may have maturities not to exceed 397 days from the date of issuance and bear interest based on, among other things, the size and maturity date of the note, the frequency of the issuance and our credit ratings, plus a spread of 5 basis points. Any borrowings under the CP program rank equally with our other unsecured debt. The notes under the CP program are not registered and are offered and issued pursuant to an exemption from registration. Due to the seasonal nature of our business, amounts borrowed can vary significantly during the period.
	As of April 30, 2015, we had $255 million of notes outstanding under the CP program, as included in “Short-term debt” in “Current Liabilities” in the Condensed Consolidated Balance Sheets, with original maturities ranging from 4 to 14 days from their dates of issuance at a weighted average interest rate of .21%. As of October 31, 2014, our outstanding notes under the CP program, included in the Condensed Consolidated Balance Sheets as stated above, were $355 million at a weighted average interest rate of .17%.
	We did not have any borrowings under the revolving syndicated credit facility for the six months ended April 30, 2015. A summary of the short-term debt activity under our CP program for the three months and six months ended April 30, 2015 is as follows.
	In millions	Three Months			Six Months
	Minimum amount outstanding during period	$	230		$	230
	Maximum amount outstanding during period	$	480		$	580
	Minimum interest rate during period	0.16		%	0.15		%
	Maximum interest rate during period	0.23		%	0.3		%
	Weighted average interest rate during period	0.21		%	0.21		%
	Our five-year revolving syndicated credit facility’s financial covenants require us to maintain a ratio of total debt to total capitalization of no greater than 70%, and our actual ratio was 54% at April 30, 2015.

Stockholders_Equity

Stockholders' Equity	6 Months Ended
	Apr. 30, 2015
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Stockholders’ Equity
	Capital Stock
	Changes in common stock for the six months ended April 30, 2015 are as follows.
	In thousands	Shares			Amount
	Balance, October 31, 2014	78,531			$	636,835
	Issued to participants in the Employee Stock Purchase Plan (ESPP)	16			612
	Issued to participants in the Dividend Reinvestment and Stock Purchase Plan	307			11,276
	Issued to participants in the Incentive Compensation Plan (ICP)	129			4,887
	Costs from issuance of common stock				(358		)
	Balance, April 30, 2015	78,983			$	653,252
	Under our effective combined debt and equity shelf registration statement, we established an at-the-market (ATM) equity sales program, including a forward sale component. On January 7, 2015, we entered into separate ATM Equity Offering Sales Agreements (Sales Agreements) with Merrill Lynch, Pierce, Fenner & Smith Incorporated (Merrill) and J.P. Morgan Securities LLC, in their capacity as agents and/or as principals (Agents). Under the terms of the Sales Agreements, we may issue and sell, through either of the Agents, shares of our common stock, up to an aggregate sales price of $170 million (subject to certain exceptions) during the period ending October 31, 2016.
	In addition to the issuance and sale of shares by us through the Agents, we may also enter into FSAs with affiliates of the Agents as Forward Purchasers. In connection with each FSA, the Forward Purchasers will, at our request, borrow from third parties and, through the Agents, sell a number of shares of our common stock equal to the number of shares underlying the FSA as its hedge. We expect to enter into separate FSAs each fiscal quarter during the term of the Sales Agreements, beginning this quarter ending April 2015.
	Under the Sales Agreements, we specify the maximum number of our shares to be sold and the minimum price per share. We will pay each Agent (or, in the case of a FSA, the Forward Purchaser through a reduced initial forward sale price) a commission of 1.5% of the sales price of all shares sold through it as sales agent under the applicable Sales Agreement. The shares offered under the Sales Agreements may be offered, issued and sold in ATM sales through the Agents or offered in connection with one or more FSAs.
	Under a FSA that we executed with Merrill on March 10, 2015, 612,000 shares were borrowed from third parties and sold by Merrill, from March 10, 2015 to April 24, 2015, at a weighted average share price of $36.83, net of adjustments. Based on the weighted average share price at the end of the trading period, the initial forward price was $36.28. Under the terms of this FSA, at our election, we may physically settle in shares, cash or net settle for all or a portion of our obligation under the agreement. We expect to settle by delivering shares. We do not expect to physically settle these shares until October 2015; however, at our election, we can settle the shares under the agreement any time prior to December 15, 2015.
	In accordance with ASC 815-40, Derivatives and Hedging - Contracts in Entity's Own Equity, we have classified the FSA as equity transactions because the forward sale transactions are indexed to our own stock and physical settlement is within our control. As a result of this classification, no amounts will be recorded in the consolidated financial statements until settlement of the FSA.
	Upon physical settlement of the FSA, delivery of our shares will result in dilution to our EPS at the date of the settlement. In quarters prior to the settlement date, any dilutive effect of the FSA on our EPS could occur during periods when the average market price per share of our common stock is above the per share adjusted forward sale price described above. See Note 3 to the condensed consolidated financial statements in this Form 10-Q for the dilutive effect of the FSA on our EPS at April 30, 2015 with the inclusion of the incremental shares in our average shares of dilutive stock as calculated under the treasury stock method.
	If we had settled the FSAs by delivery of the 612,000 shares of our common stock to the forward counterparty at April 30, 2015, we would have received net proceeds of approximately $22.2 million based on the net settlement price of $36.27 per share. Upon settlement, we intend to use the net proceeds from this FSA to finance capital expenditures, to repay outstanding short-term unsecured notes under our commercial paper program and for general corporate purposes.
	Cash dividends paid per share of common stock for the three months and six months ended April 30, 2015 and 2014 are as follows.
		Three Months							Six Months
		2015				2014			2015			2014
	Cash dividends paid per share of common stock	$	0.33			$	0.32		$	0.65		$	0.63
	Other Comprehensive Income (Loss)
	Our OCIL is a part of our accumulated OCIL and is comprised of hedging activities from our equity method investments. For further information on these hedging activities by our equity method investments, see Note 12 to the condensed consolidated financial statements in this Form 10-Q. Beginning in July 2014, another component of our accumulated OCIL is the allocation of retirement benefits to SouthStar Energy Services, LLC (SouthStar) by its majority member. Changes in each component of accumulated OCIL are presented below for the three months and six months ended April 30, 2015 and 2014.
		Changes in Accumulated OCIL(1)
		Three Months							Six Months
	In thousands	2015				2014			2015			2014
	Accumulated OCIL beginning balance, net of tax	$	(1,064	)		$	27		$	(237	)	$	(284	)
	Hedging activities of equity method investments:
	OCIL before reclassifications, net of tax	(316		)		352			(1,260		)	526
	Amounts reclassified from accumulated OCIL, net of tax	449				(359		)	566			(222		)
	Total current period activity of hedging activities of equity method investments, net of tax	133				(7		)	(694		)	304
	Net current period benefit activities of equity method investments, net of tax	(39		)					(39		)
	Accumulated OCIL ending balance, net of tax	$	(970	)		$	20		$	(970	)	$	20
	(1) Amounts in parentheses indicate debits to accumulated OCIL.
	A reconciliation of the effect on certain line items of net income on amounts reclassified out of each component of accumulated OCIL is presented below for the three months and six months ended April 30, 2015 and 2014.
		Reclassification Out of Accumulated OCIL (1)													Affected Line Items on Condensed
		Three Months							Six Months						Statements of Operations and Comprehensive Income
	In thousands	2015				2014			2015			2014
	Hedging activities of equity method investments	$	735			$	587		$	927		$	362		Income from equity method investments
	Income tax expense	(286		)		(228		)	(361		)	(140		)	Income taxes
	Hedging activities of equity method investments	449				359			566			222
	Net benefit activities of equity method investments	(64		)					(64		)				Income from equity method investments
	Income tax expense	25							25						Income taxes
	Net benefit activities of equity method investments	(39		)					(39		)
	Total reclassification for the period, net of tax	$	410			$	359		$	527		$	222
	(1) Amounts in parentheses indicate debits to accumulated OCIL.

Marketable_Securities

Marketable Securities	6 Months Ended
	Apr. 30, 2015
Marketable Securities [Abstract]
Marketable Securities	Marketable Securities
	We have marketable securities that are invested in money market and mutual funds that are liquid and actively traded on the exchanges. These securities are assets that are held in rabbi trusts established for our deferred compensation plans. For further information on the deferred compensation plans, see Note 10 to the condensed consolidated financial statements in this Form 10-Q.
	We have classified these marketable securities as trading securities since their inception as the assets are held in rabbi trusts. Trading securities are recorded at fair value on the Condensed Consolidated Balance Sheets with any gains or losses recognized currently in earnings. We do not intend to engage in active trading of the securities, and participants in the deferred compensation plans may redirect their deemed investments at any time. We have matched the current portion of the deferred compensation liability with the current asset and the noncurrent deferred compensation liability with the noncurrent asset; the current asset portion is included in “Other current assets” in “Current Assets” in the Condensed Consolidated Balance Sheets.
	The money market investments in the trusts approximate fair value due to the short period of time to maturity. The fair values of the equity securities are based on quoted market prices as traded on the exchanges. The composition of these securities as of April 30, 2015 and October 31, 2014 is as follows.
		30-Apr-15				31-Oct-14
	In thousands	Cost		Fair		Cost		Fair
				Value				Value
	Current trading securities:
	Money markets	$	47	$	47	$	22	$	22
	Mutual funds	121		201		106		192
	Total current trading securities	168		248		128		214
	Noncurrent trading securities:
	Money markets	484		484		447		447
	Mutual funds	3,563		4,221		2,598		3,280
	Total noncurrent trading securities	4,047		4,705		3,045		3,727
	Total trading securities	$	4,215	$	4,953	$	3,173	$	3,941

Financial_Instruments_Related_

Financial Instruments & Related Fair Value	6 Months Ended
	Apr. 30, 2015
Financial Instruments And Related Fair Value [Abstract]
Financial Instruments and Related Fair Value	Financial Instruments and Related Fair Value
	Derivative Assets and Liabilities under Master Netting Arrangements
	We maintain brokerage accounts to facilitate transactions that support our gas cost hedging plans. The accounting guidance related to derivatives and hedging requires that we use a gross presentation, based on our election, for the fair value amounts of our derivative instruments. We use long position gas purchase options to provide some level of protection for our customers in the event of significant commodity price increases. As of April 30, 2015 and October 31, 2014, we had long gas purchase options providing total coverage of 32.7 million dekatherms and 29.2 million dekatherms, respectively. The long gas purchase options held at April 30, 2015 are for the period from June 2015 through May 2016.
	Fair Value Measurements
	We use financial instruments that are not designated as hedges for accounting purposes to mitigate commodity price risk for our customers. We also have marketable securities that are held in rabbi trusts established for our deferred compensation plans. We classify fair value balances based on the observance of inputs into the fair value hierarchy levels as set forth in the fair value accounting guidance and fully described in “Fair Value Measurements” in Note 1 to the consolidated financial statements in our Form 10-K for the year ended October 31, 2014.
	The following table sets forth, by level of the fair value hierarchy, our financial assets that were accounted for at fair value on a recurring basis as of April 30, 2015 and October 31, 2014. Our assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of fair value assets and liabilities and their consideration within the fair value hierarchy levels. We have had no transfers between any level during the three months ended April 30, 2015 and 2014. We present our derivative positions at fair value on a gross basis and have only asset positions for all periods presented for the fair value of purchased call options held for our utility operations. There are no derivative contracts in a liability position, and we have posted no cash collateral nor received any cash collateral under our master netting arrangements. Therefore, we have no offsetting disclosures for financial assets or liabilities for our derivatives held for utility operations. Our derivatives held for utility operations are held with one broker as our counterparty.
	Recurring Fair Value Measurements as of April 30, 2015
	In thousands	Quoted Prices			Significant		Significant			Effects of		Total
		in Active			Other		Unobservable			Netting and		Carrying
		Markets			Observable		Inputs			Cash Collateral		Value
		(Level 1)			Inputs		(Level 3)			Receivables /
					(Level 2)					Payables
	Assets:
	Derivatives held for utility operations	$	2,142		$	—	$	—		$	—	$	2,142
	Debt and equity securities held as trading securities:
	Money markets	531			—		—			—		531
	Mutual funds	4,422			—		—			—		4,422
	Total fair value assets	$	7,095		$	—	$	—		$	—	$	7,095
	Recurring Fair Value Measurements as of October 31, 2014
	In thousands	Quoted Prices			Significant		Significant			Effects of		Total
		in Active			Other		Unobservable			Netting and		Carrying
		Markets			Observable		Inputs			Cash Collateral		Value
		(Level 1)			Inputs		(Level 3)			Receivables /
					(Level 2)					Payables
	Assets:
	Derivatives held for utility operations	$	4,898		$	—	$	—		$	—	$	4,898
	Debt and equity securities held as trading securities:
	Money markets	469			—		—			—		469
	Mutual funds	3,472			—		—			—		3,472
	Total fair value assets	$	8,839		$	—	$	—		$	—	$	8,839
	Our regulated utility segment derivative instruments are used in accordance with programs filed with or approved by the NCUC, the PSCSC and the TRA to hedge the impact of market fluctuations in natural gas prices. These derivative instruments are accounted for at fair value each reporting period. In accordance with regulatory requirements, the net gains and losses related to these derivatives are reflected in purchased gas costs and ultimately passed through to customers through our purchase gas adjustment (PGA) procedures. In accordance with accounting provisions for rate-regulated activities, the unrecovered amounts related to these instruments are reflected as a regulatory asset or liability, as appropriate, in “Amounts due from customers” or “Amounts due to customers” in Note 2 to the condensed consolidated financial statements. These derivative instruments are exchange-traded derivative contracts. Exchange-traded contracts are generally based on unadjusted quoted prices in active markets and are classified within Level 1.
	Trading securities include assets in rabbi trusts established for our deferred compensation plans and are included in “Marketable securities, at fair value” in “Noncurrent Assets” in the Condensed Consolidated Balance Sheets. Securities classified within Level 1 include funds held in money market and mutual funds which are highly liquid and are actively traded on the exchanges.
	Our long-term debt is recorded at unamortized cost. In developing the fair value of our long-term debt, we use a discounted cash flow technique, consistently applied, that incorporates a developed discount rate using long-term debt similarly rated by credit rating agencies combined with the U.S. Treasury benchmark, with consideration given to maturities, redemption terms and credit ratings similar to our debt issuances. The carrying amount and fair value of our long-term debt, including the current portion, which is classified within Level 2, are shown below.
	In thousands	Carrying			Fair Value
		Amount  (1)
	As of April 30, 2015	$	1,425,000		$	1,634,164
	As of October 31, 2014	1,425,000			1,617,453
	(1) Excludes discount on issuance of notes of $557 and $570 as of April 30, 2015 and October 31, 2014, respectively.
	Quantitative and Qualitative Disclosures
	The costs of our financial price hedging options for natural gas and all other costs related to hedging activities of our regulated gas costs are recorded in accordance with our regulatory tariffs approved by our state regulatory commissions, and thus are not accounted for as designated hedging instruments under derivative accounting standards. As required by the accounting guidance, the fair value of our financial options is presented on a gross basis with only asset positions for all periods presented. There are no derivative contracts in a liability position, and we have posted no cash collateral nor received any cash collateral under our master netting arrangements; therefore, we have no offsetting disclosures for financial assets or liabilities for our financial option derivatives.
	The following table presents the fair value and balance sheet classification of our financial options for natural gas as of April 30, 2015 and October 31, 2014.
	Fair Value of Derivative Instruments
		April 30,			October 31,
	In thousands	2015			2014
	Derivatives Not Designated as Hedging Instruments under Derivative Accounting Standards:
	Asset Financial Instruments:
	Current Assets – Gas purchase derivative assets (June 2015 - May 2016)	$	2,142
	Current Assets – Gas purchase derivative assets (December 2014 - November 2015)				$	4,898
	We purchase natural gas for our regulated operations for resale under tariffs approved by state regulatory commissions. We recover the cost of gas purchased for regulated operations through PGA procedures. Our risk management policies allow us to use financial instruments to hedge commodity price risks, but not for speculative trading. The strategy and objective of our hedging programs are to use these financial instruments to reduce gas cost volatility for our customers. Accordingly, the operation of the hedging programs on the regulated utility segment as a result of the use of these financial derivatives is initially deferred as amounts due from customers included as “Regulatory Assets” or amounts due to customers included as “Regulatory Liabilities” in Note 2 to the condensed consolidated financial statements and recognized in the Condensed Consolidated Statements of Comprehensive Income as a component of “Cost of Gas” when the related costs are recovered through our rates.
	The following table presents the impact that financial instruments not designated as hedging instruments under derivative accounting standards would have had on the Condensed Consolidated Statements of Comprehensive Income for the three months and six months ended April 30, 2015 and 2014, absent the regulatory treatment under our approved PGA procedures.
		Amount of Gain (Loss) Recognized										Location of Gain (Loss)
		on Derivative Instruments and Deferred Under PGA Procedures										Recognized through
												PGA Procedures
		Three Months Ended					Six Months Ended
		April 30					April 30
	In thousands	2015			2014		2015			2014
	Gas purchase options	$	(1,731	)	$	3,297	$	(2,289	)	$	7,826	Cost of Gas
	In Tennessee, the cost of gas purchase options and all other costs related to hedging activities up to 1% of total annual gas costs are approved for recovery under the terms and conditions of our TIP as approved by the TRA. In South Carolina, the costs of gas purchase options are subject to and are approved for recovery under the terms and conditions of our gas hedging plan as approved by the PSCSC. In North Carolina, the costs associated with our hedging program are treated as gas costs subject to an annual cost review proceeding by the NCUC.
	Credit and Counterparty Risk
	Information regarding our credit and counterparty risk is set forth in Note 7 to the consolidated financial statements in our Form 10-K for the year ended October 31, 2014. During the three months ended April 30, 2015, there were no material changes in our credit and counterparty risk.
	We enter into contracts with third parties to buy and sell natural gas. A significant portion of these transactions are with, or are associated with, energy producers, utility companies, off-system municipalities and natural gas marketers. The amount included in “Trade accounts receivable” in “Current Assets” in the Condensed Consolidated Balance Sheets attributable to these entities amounted to $4.2 million, or approximately 5%, of our gross trade accounts receivable at April 30, 2015. Our policy requires counterparties to have an investment-grade credit rating at the time of the contract, or in situations where counterparties do not have investment-grade or functionally equivalent credit ratings, our policy requires credit enhancements that include letters of credit or parental guaranties. In either circumstance, our policy specifies limits on the contract amount and duration based on the counterparty’s credit rating and/or credit support. In order to minimize our exposure, we continually re-evaluate third-party creditworthiness and market conditions and modify our requirements accordingly.
	Risk Management
	Our financial derivative instruments do not contain material credit-risk-related or other contingent features that could require us to make accelerated payments.
	We seek to identify, assess, monitor and manage risk in accordance with defined policies and procedures under the direction of the Treasurer and Chief Risk Officer and our Enterprise Risk Management program, including our Energy Price Risk Management Committee. Risk management is guided by senior management with Board of Directors oversight, and senior management takes an active role in the development of policies and procedures.

Commitments_and_Contingent_Lia

Commitments and Contingent Liabilities	6 Months Ended
	Apr. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingent Liabilities	Commitments and Contingent Liabilities
	Long-term Contracts
	We routinely enter into long-term gas supply commodity and capacity commitments and other agreements that commit future cash flows to acquire services we need in our business. These commitments include pipeline and storage capacity contracts and gas supply contracts to provide service to our customers and telecommunication and information technology contracts and other purchase obligations. Costs arising from the gas supply commodity and capacity commitments, while significant, are pass-through costs to our customers and are generally fully recoverable through our PGA procedures and prudence reviews in North Carolina and South Carolina and under the TIP in Tennessee. The time periods for fixed payments under pipeline and storage capacity contracts are up to twenty-one years. The time periods for fixed payments under gas supply contracts are up to two years. The time periods for the telecommunications and technology outsourcing contracts, maintenance fees for hardware and software applications, usage fees, local and long-distance costs and wireless service are up to four years. Other purchase obligations consist primarily of commitments for pipeline products, vehicles, equipment and contractors.
	Certain storage and pipeline capacity contracts require the payment of demand charges that are based on rates approved by the Federal Energy Regulatory Commission (FERC) in order to maintain our right to access the natural gas storage or the pipeline capacity on a firm basis during the contract term. The demand charges that are incurred in each period are recognized in the Condensed Consolidated Statements of Comprehensive Income as part of gas purchases and included in “Cost of Gas.”
	Leases
	We lease certain buildings, land and equipment for use in our operations under noncancelable operating leases. We account for these leases by recognizing the future minimum lease payments as expense on a straight-line basis over the respective minimum lease terms under current accounting guidance.
	Legal
	We have only routine litigation in the normal course of business. We do not expect any of these routine litigation matters to have a material effect, either individually or in the aggregate, on our financial position, results of operations or cash flows.
	Letters of Credit
	We use letters of credit to guarantee claims from self-insurance under our general and automobile liability policies. We had $1.7 million in letters of credit that were issued and outstanding as of April 30, 2015. Additional information concerning letters of credit is included in Note 5 to the condensed consolidated financial statements in this Form 10-Q.
	Surety Bonds
	In the normal course of business, we are occasionally required to provide financial commitments in the form of surety bonds to third parties as a guarantee of our performance on commercial obligations. We have agreements that indemnify certain issuers of surety bonds against losses that they may incur as a result of executing surety bonds on our behalf. If we were to fail to perform according to the terms of the underlying contract, any draws upon surety bonds issued on our behalf would then trigger our payment obligation to the surety bond issuer. As of April 30, 2015, we had open surety bonds with a total contingent obligation of $6.6 million.
	Environmental Matters
	Our three regulatory commissions have authorized us to utilize deferral accounting in connection with environmental costs. Accordingly, we have established regulatory assets for actual environmental costs incurred and for estimated environmental liabilities recorded. There were no material changes in the status of environmental-related matters during the six months ended April 30, 2015.
	As of April 30, 2015, our estimated undiscounted environmental liability totaled $1.1 million for manufactured gas production sites for which we retain remediation responsibility and for our underground storage tanks, which have been removed and for which we are waiting on a decision from the North Carolina Department of Environment and Natural Resources as to their final disposition. The costs we reasonably expect to incur are estimated using assumptions based on actual costs incurred, the timing of future payments and inflation factors, among others.
	Further evaluation of environmental liabilities could significantly affect recorded amounts; however, we believe that the ultimate resolution of these matters will not have a material effect on our financial position, results of operations or cash flows.
	Additional information concerning commitments and contingencies is set forth in Note 8 to the consolidated financial statements of our Form 10-K for the year ended October 31, 2014.

Employee_Benefit_Plans

Employee Benefit Plans	6 Months Ended
	Apr. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plans	Employee Benefit Plans
	Components of the net periodic benefit cost for our defined benefit pension plans and our other postretirement employee benefits (OPEB) plan for the three months ended April 30, 2015 and 2014 are presented below.
		Qualified Pension						Nonqualified				Other Benefits
								Pension
	In thousands	2015			2014			2015		2014		2015			2014
	Service cost	$	3,050		$	2,750		$	—	$	—	$	295		$	277
	Interest cost	2,975			2,950			52		45		369			362
	Expected return on plan assets	(5,925		)	(5,700		)	—		—		(459		)	(457		)
	Amortization of prior service (credit) cost	(550		)	(550		)	58		20		—			—
	Amortization of actuarial loss	2,050			1,875			21		12		7			—
	Total	$	1,600		$	1,325		$	131	$	77	$	212		$	182
	Components of the net periodic benefit cost for our defined benefit pension plans and our OPEB plan for the six months ended April 30, 2015 and 2014 are presented below.
		Qualified Pension						Nonqualified				Other Benefits
								Pension
	In thousands	2015			2014			2015		2014		2015			2014
	Service cost	$	6,100		$	5,500		$	—	$	—	$	591		$	554
	Interest cost	5,950			5,900			104		90		738			724
	Expected return on plan assets	(11,850		)	(11,400		)	—		—		(919		)	(915		)
	Amortization of prior service (credit) cost	(1,100		)	(1,100		)	115		41		—			—
	Amortization of actuarial loss	4,100			3,750			43		23		15			—
	Total	$	3,200		$	2,650		$	262	$	154	$	425		$	363
	In November 2014, we contributed $10 million to the qualified pension plan, and in January 2015, we contributed $1.4 million to the money purchase pension plan. During the six months ended April 30, 2015, we contributed $.2 million to the nonqualified pension plans. We anticipate that we will contribute the following additional amounts to our plans in 2015.
	In thousands
	Nonqualified pension plans	$	282
	OPEB plan	1,500
	We have a non-qualified defined contribution restoration plan (DCR plan) for all officers at the vice president level and above where benefits payable under the plan are funded annually. For the six months ended April 30, 2015, we contributed $.5 million to this plan. Participants may not contribute to the DCR plan. We have a voluntary deferral plan for the benefit of all director-level employees and officers, where we make no contributions to this plan. Both deferred compensation plans are funded through rabbi trusts with a bank as the trustee. As of April 30, 2015, we have a liability of $5.1 million for these plans.
	See Note 7 and Note 8 to the condensed consolidated financial statements in this Form 10-Q for information on the investments in marketable securities that are held in the trusts.

Employee_ShareBased_Plans

Employee Share-Based Plans	6 Months Ended
	Apr. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Employee Share-Based Plans	Employee Share-Based Plans
	Under our shareholder approved ICP, eligible officers and other participants are awarded units that pay out depending upon the level of performance achieved by Piedmont during three-year incentive plan performance periods. Distribution of those awards may be made in the form of shares of common stock and withholdings for payment of applicable taxes on the compensation. These plans require that a minimum threshold performance level be achieved in order for any award to be distributed. For the three months and six months ended April 30, 2015 and 2014, we recorded compensation expense, and as of April 30, 2015 and October 31, 2014, we accrued a liability for these awards based on the fair market value of our stock at the end of each quarter. The liability is re-measured to market value at the settlement date.
	Also under our approved ICP, 64,700 unvested retention stock units were granted to our President and Chief Executive Officer in December 2011. During the five-year vesting period, any dividend equivalents will accrue on these stock units and be converted into additional units at the same rate and based on the closing price on the same payment date as dividends on our common stock. The stock units will vest, payable in the form of shares of common stock and withholdings for payment of applicable taxes on the compensation, over a five-year period only if he is an employee on each vesting date. In accordance with the vesting schedule, 20% of the units vested on December 15, 2014, 30% of the units vest on December 15, 2015 and 50% of the units vest on December 15, 2016. For the three months and six months ended April 30, 2015 and 2014, we recorded compensation expense, and as of April 30, 2015 and October 31, 2014, we accrued a liability for this award based on the fair market value of our stock at the end of the quarter. The liability is re-measured to market value at the settlement date.
	On December 15, 2014, 20% of the grant, including accrued dividends, vested for a total of 14,461 shares of common stock. After the withholding of $.3 million for federal and state income taxes, our President and Chief Executive Officer received 7,231 shares at the New York Stock Exchange composite closing price on December 12, 2014 of $37.89 per share.
	At the time of distribution of awards under the ICP, the number of shares issuable is reduced by the withholdings for payment of applicable income taxes for each participant. The participant may elect income tax withholdings at or above the minimum statutory withholding requirements. The maximum withholdings allowed under the ICP is 50%. To date, shares withheld for payment of applicable income taxes have been immaterial. We present these net shares issued in the Condensed Consolidated Statements of Stockholders’ Equity and in Note 6 to the condensed consolidated financial statements in this Form 10-Q.
	The compensation expense related to the incentive compensation plans for the three months and six months ended April 30, 2015 and 2014, and the amounts recorded as liabilities in “Other noncurrent liabilities” in “Noncurrent Liabilities” with the current portion recorded in “Other current liabilities” in “Current Liabilities” in the Condensed Consolidated Balance Sheets as of April 30, 2015 and October 31, 2014 are presented below.
		Three Months				Six Months
	In thousands	2015		2014		2015		2014
	Compensation expense	$	1,050	$	2,103	$	3,279	$	4,203
		April 30,		October 31,
		2015		2014
	Liability	$	11,143	$	15,130
	On a quarterly basis, we issue shares of common stock under the ESPP and account for the issuance as an equity transaction. The exercise price is calculated as 95% of the fair market value on the purchase date of each quarter where fair market value is determined by calculating the average of the high and low trading prices on the purchase date.

Equity_Method_Investments

Equity Method Investments	6 Months Ended
	Apr. 30, 2015
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Equity Method Investments
	The condensed consolidated financial statements include the accounts of wholly-owned subsidiaries whose investments in joint venture, energy-related businesses are accounted for under the equity method. Our ownership interest in each entity is included in “Equity method investments in non-utility activities” in “Noncurrent Assets” in the Condensed Consolidated Balance Sheets. Earnings or losses from equity method investments are included in “Income from equity method investments” in “Other Income (Expense)” in the Condensed Consolidated Statements of Comprehensive Income.
	Ownership Interests
	We have the following membership interests in these companies as of April 30, 2015 and October 31, 2014, respectively.
	Equity Method Investment	Interest			Activity
	Atlantic Coast Pipeline, LLC (ACP)	10	%		To develop, construct, own and operate approximately 550 miles of interstate natural gas pipeline with associated compression from West Virginia through Virginia into eastern North Carolina in order to provide interstate natural gas transportation services of Marcellus and Utica gas supplies into southeastern markets; regulated by the FERC
	Cardinal Pipeline Company, L.L.C (Cardinal)	21.49	%		Intrastate pipeline located in North Carolina; regulated by the NCUC
	Constitution Pipeline Company LLC (Constitution)	24	%		To develop, construct, own and operate approximately 120 miles of interstate natural gas pipeline, and related facilities, connecting shale natural gas supplies and gathering systems in Susquehanna County, Pennsylvania, to Iroquois Gas Transmission and Tennessee Gas Pipeline systems in New York; regulated by the FERC
	Hardy Storage Company (Hardy Storage)	50	%		Underground interstate storage facility located in Hardy and Hampshire Counties, West Virginia; regulated by the FERC
	Pine Needle LNG Company, L.L.C. (Pine Needle)	45	%		Interstate LNG storage facility located in North Carolina; regulated by the FERC
	SouthStar	15	%		Energy services company primarily selling natural gas in the unregulated retail gas market to residential, commercial and industrial customers in the eastern United States, primarily Georgia and Illinois
	Accumulated Other Comprehensive Income (Loss)
	As an equity method investee, we record the effect of certain transactions in our accumulated OCIL. Cardinal and Pine Needle enter into interest-rate swap agreements to modify the interest expense characteristics of their unsecured long-term debt which is nonrecourse to its members. SouthStar uses financial contracts in the form of futures, options and swaps, all considered to be derivatives, to moderate the effect of price and weather changes on the timing of its earnings; fair value of these financial contracts is based on selected market indices. Beginning in July 2014, retirement benefits were allocated to SouthStar by its majority member with the activity of prescribed benefit expense items reflected in accumulated OCIL. For these transactions with these equity method investees, we record our share of movements in the market value of these hedged agreements and contracts and retirement benefit items in “Accumulated other comprehensive loss” in “Stockholders’ equity” in the Condensed Consolidated Balance Sheets; the detail of our share of the market value of the various financial instruments and the retirement benefits are presented in “Other Comprehensive Income (Loss), net of tax” in the Condensed Consolidated Statements of Comprehensive Income.
	Related Party Transactions
	We have related party transactions as a customer of our investments. For each period of the three months and six months ended April 30, 2015 and 2014, these gas costs and the amounts we owed to our equity method investees, as of April 30, 2015 and October 31, 2014 are as follows.
	Related Party	Type of Expense		Cost of Gas (1)																Trade accounts payable (2)
				Three Months								Six Months								April 30,				October 31,
	In thousands			2015				2014				2015				2014				2015				2014
	Cardinal	Transportation costs		$	2,135			$	2,164			$	4,349			$	4,404			$	720			$	747
	Hardy Storage	Gas storage costs		2,322				2,392				4,645				4,817				774				774
	Pine Needle	Gas storage costs		2,840				2,701				5,776				5,494				957				989
	Totals			$	7,297			$	7,257			$	14,770			$	14,715			$	2,451			$	2,510
	(1) In the Condensed Consolidated Statements of Comprehensive Income.
	(2) In the Condensed Consolidated Balance Sheets.
	We have related party transactions as we sell wholesale gas supplies to SouthStar. For each period of the three months and six months ended April 30, 2015 and 2014, our operating revenues from these sales and the amounts SouthStar owed us as of April 30, 2015 and October 31, 2014 are as follows.
		Operating Revenues (1)																Trade accounts receivable (2)
		Three Months								Six Months								April 30,				October 31,
	In thousands	2015				2014				2015				2014				2015				2014
	Operating revenues	$	187			$	475			$	583			$	907			$	177			$	460
	(1) In the Condensed Consolidated Statements of Comprehensive Income.
	(2) In the Condensed Consolidated Balance Sheets.
	Other Information – Constitution
	A subsidiary of The Williams Companies is the operator of the project. The total estimated cost of the project is $875 million, including an allowance for funds used during construction (AFUDC).
	We have committed to fund an amount in proportion to our ownership interest for the development and construction of the new pipeline, which is expected to cost approximately $785 million, excluding AFUDC, at the project level. Our contributions for the quarter and fiscal year 2015 were $4.8 million and $9.7 million, respectively, with our total equity contribution for the project totaling $63.3 million to date. On December 2, 2014, the FERC issued a certificate of public convenience and necessity approving construction of the Constitution pipeline. The target in-service date of the project is the second half of 2016, which has been extended due to a longer than expected regulatory and permitting process. The capacity of the pipeline is 100% subscribed under fifteen-year service agreements with two Marcellus producer-shippers with a negotiated rate structure.
	Other Information – ACP
	A subsidiary of Dominion Resources, Inc. will be the operator of the pipeline. The total cost of the project is expected to be between $4.5 billion to $5 billion, excluding financing costs. Members anticipate obtaining project financing for 70% of the total costs during the construction period, and a capitalization ratio of 50% debt and 50% equity when operational.
	We have committed to fund an amount in proportion to our ownership interest for the development and construction of the new pipeline. If project financing is obtained, our total expected contributions would be between $225 million to $250 million. Our contributions for the quarter and fiscal year 2015 were $.7 million and $5.8 million, respectively, with contributions to the project beginning November 2014.
	ACP is regulated by the FERC and subject to state and other federal approvals with a target in-service date of late 2018. The capacity of ACP is substantially subscribed by affiliates of the members of ACP, other utilities and related companies under twenty-year contracts.
	In November 2014, the FERC authorized the ACP pre-filing process. In February 2015, ACP, along with Dominion Transmission, Inc. (DTI), filed a notice of intent to prepare its environmental impact statement for the project and DTI’s supply header project affecting ACP. ACP expects to file its FERC application in the summer or fall of 2015, receive the FERC certificate of public convenience and necessity in the summer of 2016 and begin construction thereafter.
	On March 2, 2015, ACP entered into a Precedent Agreement with DTI for supply header transportation services. Under the Precedent Agreement, ACP is required to provide assurance of its ability to meet its financial obligations to DTI. DTI has informed ACP that ACP, independent of its members, is not currently creditworthy as required by DTI’s FERC Gas Tariff. ACP requested that its members provide proportionate assurance of ACP’s ability to meet its financial obligations under the Precedent Agreement, which the Piedmont member provided through an Equity Contribution Agreement between Piedmont and ACP where Piedmont committed to make funds available to the Piedmont member for it to pay and perform its obligations under the ACP Limited Liability Company Agreement. This commitment is capped at $15.2 million. This commitment ceases when DTI acknowledges that ACP is independently creditworthy in accordance with the Precedent Agreement, termination or expiration of the Precedent Agreement, or when we are no longer a member of ACP.

Variable_Interest_Entities

Variable Interest Entities	6 Months Ended
	Apr. 30, 2015
Variable Interest Entity, Not Primary Beneficiary, Disclosures [Abstract]
Variable Interest Entities	Variable Interest Entities
	As of April 30, 2015, we have determined that we are not the primary beneficiary under variable interest entity (VIE) accounting guidance in any of our equity method investments, as discussed in Note 12 to the condensed consolidated financial statements in this Form 10-Q. Based on our involvement in these investments, we do not have the power to direct the activities of these investments that most significantly impact the VIE’s economic performance. As we are not the consolidating investor, we will continue to apply equity method accounting to these investments. Our maximum loss exposure related to these equity method investments is limited to our equity investment in each entity. As of April 30, 2015 and October 31, 2014, our investment balances are as follows.
	In thousands	April 30,		October 31,
		2015		2014
	Cardinal	$	15,501	$	16,073
	Pine Needle	18,237		18,689
	SouthStar	38,396		40,965
	Hardy Storage	38,738		37,179
	Constitution	69,784		57,255
	ACP	5,335		10
	Total equity method investments in non-utility activities	$	185,991	$	170,171
	We have also reviewed various lease arrangements, contracts to purchase, sell or deliver natural gas and other agreements in which we hold a variable interest. In these cases, we have determined that we are not the primary beneficiary of the related VIE because we do not have the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance, or the obligation to absorb losses of the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE.

Business_Segments

Business Segments	6 Months Ended
	Apr. 30, 2015
Segment Reporting [Abstract]
Business Segments	Business Segments
	We have three reportable business segments, regulated utility, regulated non-utility, and unregulated non-utility activities. Our segments are identified based on products and services, regulatory environments and our current corporate organization and business decision-making activities. The regulated utility segment is the gas distribution business, where we include the operations of merchandising and its related service work and home service agreements, with activities conducted by the parent company. Although the operations of our regulated utility segment are located in three states under the jurisdiction of individual state regulatory commissions, the operations are managed as one unit having similar economic and risk characteristics within one company.
	Operations of our regulated non-utility activities segment are comprised of our equity method investments in joint ventures with regulated activities that are held by our wholly-owned subsidiaries. Operations of our unregulated non-utility activities segment are comprised primarily of our equity method investment in a joint venture with unregulated activities that is held by a wholly-owned subsidiary; activities of our other minor subsidiaries are also included.
	Operations of the regulated utility segment are reflected in “Operating Income” in the Condensed Consolidated Statements of Comprehensive Income. Operations of the regulated non-utility activities and unregulated non-utility activities segments are included in the Condensed Consolidated Statements of Comprehensive Income in “Other Income (Expense)” in “Income from equity method investments” and “Non-operating income.”
	Our chief operating decision maker is the executive management team. We produce consolidated financial information internally that is supplemented with separate non-utility activity reporting that is used regularly to make operating decisions and assess performance of our three business segments. We evaluate the performance of the regulated utility segment based on margin, operations and maintenance expenses and operating income. We evaluate the performance of the regulated and unregulated non-utility activities segments based on earnings from our cash flows in the ventures.
	The basis of segmentation and the basis of the measurement of segment profit or loss are the same as reported in the consolidated financial statements in our Form 10-K for the year ended October 31, 2014. The information for 2014 has been recast to align with management's view of the non-utility activities.
	Operations by segment for the three months and six months ended April 30, 2015 and 2014 are presented below.
		Regulated Utility						Regulated						Unregulated						Total
								Non-Utility						Non-Utility
								Activities						Activities
	In thousands	2015			2014			2015			2014			2015			2014			2015		2014
	Three Months
	Revenues from external customers	$	424,924		$	462,247		$	—		$	—		$	—		$	—		$	424,924	$	462,247
	Margin	225,621			211,523			—			—			—			—			225,621		211,523
	Operations and maintenance expenses	71,424			70,193			20			8			9			13			71,453		70,214
	Income from equity method investments	—			—			3,577			2,467			12,265			11,893			15,842		14,360
	Operating income (loss) before income taxes	111,532			103,489			(20		)	(8		)	(14		)	(17		)	111,498		103,464
	Income before income taxes	92,918			88,999			3,557			2,459			12,252			11,876			108,727		103,334
	Six Months
	Revenues from external customers	$	1,032,196		$	1,119,980		$	—		$	—		$	—		$	—		$	1,032,196	$	1,119,980
	Margin	495,691			473,035			—			—			—			—			495,691		473,035
	Operations and maintenance expenses	137,574			130,832			51			14			47			32			137,672		130,878
	Income from equity method investments	—			—			7,348			5,574			16,759			18,728			24,107		24,302
	Operating income (loss) before income taxes	273,562			265,610			(51		)	(14		)	(135		)	(119		)	273,376		265,477
	Income before income taxes	237,318			240,268			7,297			5,560			16,625			18,608			261,240		264,436
	Reconciliations to the condensed consolidated statements of comprehensive income for the three months and six months ended April 30, 2015 and 2014 are presented below.
		Three Months						Six Months
	In thousands	2015			2014			2015			2014
	Operating Income:
	Segment operating income before income taxes	$	111,498		$	103,464		$	273,376		$	265,477
	Utility income taxes	(36,409		)	(36,190		)	(92,680		)	(95,992		)
	Regulated non-utility activities operating loss before income taxes	20			8			51			14
	Unregulated non-utility activities operating loss before income taxes	14			17			135			119
	Operating income	$	75,123		$	67,299		$	180,882		$	169,618
	Net Income:
	Income before income taxes for reportable segments	$	108,727		$	103,334		$	261,240		$	264,436
	Income taxes	(42,325		)	(40,794		)	(101,860		)	(104,324		)
	Total	$	66,402		$	62,540		$	159,380		$	160,112

Subsequent_Events

Subsequent Events	6 Months Ended
	Apr. 30, 2015
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events
	We monitor significant events occurring after the balance sheet date and prior to the issuance of the financial statements to determine the impacts, if any, of events on the financial statements to be issued. All subsequent events of which we are aware were evaluated. For information on subsequent event disclosure items related to regulatory matters, see Note 2 to the condensed consolidated financial statements in this Form 10-Q.

Recovered_Sheet1

Summary Of Significant Accounting Policies (Policies)	6 Months Ended
	Apr. 30, 2015
Accounting Policies [Abstract]
Unaudited Interim Financial Information and Seasonality	The unaudited condensed consolidated financial statements include all normal recurring adjustments necessary for a fair presentation of the statement of financial position at April 30, 2015 and October 31, 2014, the results of operations for three months and six months ended April 30, 2015 and 2014, and cash flows and stockholders’ equity for the six months ended April 30, 2015 and 2014. Our business is seasonal in nature. The results of operations for the three months and six months ended April 30, 2015 do not necessarily reflect the results to be expected for the full year.
	The condensed consolidated financial statements have not been audited. We have prepared the unaudited condensed consolidated financial statements under the rules of the Securities and Exchange Commission (SEC). Therefore, certain financial information and note disclosures normally included in annual financial statements prepared in conformity with generally accepted accounting principles (GAAP) in the United States of America are omitted in this interim report under these SEC rules and regulations. These financial statements should be read in conjunction with the Consolidated Financial Statements and Notes included in our Form 10-K for the year ended October 31, 2014.
Use of Estimates	In accordance with GAAP, we make certain estimates and assumptions regarding reported amounts of assets, liabilities, revenues and expenses and the related disclosures, using historical experience and other assumptions that we believe are reasonable at the time. Our estimates may involve complex situations requiring a high degree of judgment in the application and interpretation of existing literature or in the development of estimates that impact our financial statements. These estimates and assumptions affect the reported amounts of assets and liabilities as of the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates and assumptions, which are evaluated on a continual basis.
Rate Regulated Basis Of Accounting	Our utility operations are subject to regulation with respect to rates, service area, accounting and various other matters by the regulatory commissions in the states in which we operate. The accounting regulations provide that rate-regulated public utilities account for and report assets and liabilities consistent with the economic effect of the manner in which independent third-party regulators establish rates. In applying these regulations, we capitalize certain costs and benefits as regulatory assets and liabilities, respectively, in order to provide for recovery from or refund to utility customers in future periods. Generally, regulatory assets are amortized to expense and regulatory liabilities are amortized to income over the period authorized by our regulators.
Fair Value Measurements	We have financial and nonfinancial assets and liabilities subject to fair value measurement. The financial assets and liabilities measured and carried at fair value in the Condensed Consolidated Balance Sheets are cash and cash equivalents, marketable securities held in rabbi trusts established for our deferred compensation plans and derivative assets and liabilities, if any, that are held for our utility operations. The carrying values of receivables, short-term debt, accounts payable, accrued interest and other current assets and liabilities approximate fair value as all amounts reported are to be collected or paid within one year. Our nonfinancial assets and liabilities include our qualified pension and postretirement plan assets and liabilities that are recorded at fair value in the Condensed Consolidated Balance Sheets in accordance with employers’ accounting and related disclosures of postretirement plans.
	Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date, or exit date. We utilize market data or assumptions that market participants would use in valuing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, market corroborated or generally unobservable. We primarily apply the market approach for fair value measurements and endeavor to utilize the best available information. Accordingly, we use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs.
Investment, Policy	The fair values of the equity securities are based on quoted market prices as traded on the exchanges.
	Trading securities are recorded at fair value on the Condensed Consolidated Balance Sheets with any gains or losses recognized currently in earnings.
Earnings per Share	We compute basic earnings per share (EPS) using the daily weighted average number of shares of common stock outstanding during each period. In the calculation of fully diluted EPS, shares of common stock to be issued under approved incentive compensation plans and forward sale agreements (FSAs) are contingently issuable shares, as determined by applying the treasury stock method, and are added to average common shares outstanding, resulting in a potential reduction in diluted EPS.
Subsequent Events	We monitor significant events occurring after the balance sheet date and prior to the issuance of the financial statements to determine the impacts, if any, of events on the financial statements to be issued.

Summary_Of_Significant_Account1

Summary Of Significant Accounting Policies (Tables)	6 Months Ended
	Apr. 30, 2015
Accounting Policies [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	Recently Issued Accounting Guidance
	Guidance	Description	Effective date	Effect on the financial statements or other significant matters
	ASU 2014-09, May 2014, Revenue from Contracts with Customers (Topic 606)	Under the new standard, entities will recognize revenue to depict the transfer of goods and services to customers in amounts that reflect the payment to which the entity expects to be entitled in exchange for those goods or services. The disclosure requirements will provide information about the nature, amount, timing and uncertainty of revenue and cash flows from an entity’s contracts with customers.	Annual periods beginning after December 15, 2016, and interim periods within those periods.	We have been evaluating the effect on our financial position, results of operations and cash flows. The evaluation includes identifying revenue streams by like contracts to allow for ease of implementation. In our evaluation, we are following the efforts of an accounting utility subgroup and its issuance of a revenue implementation guide.
			The Financial Accounting Standards Board (FASB) proposed the deferral of the effective date to annual periods beginning after December 15, 2017 (beginning November 1, 2018 for us) and interim periods within that period, with early adoption permitted for annual periods beginning after December 15, 2016.
	ASU 2014-15, August 2014, Presentation of Financial Statements - Going Concern (Subtopic 205-40)	The FASB issued accounting guidance on determining when and how reporting entities must disclose going concern uncertainties in their financial statements. The new standard requires management to perform interim and annual assessments of an entity's ability to continue as a going concern within one year of the date of issuance of the entity's financial statements. An entity must provide certain disclosures if there is a "substantial doubt about the entity's ability to continue as a going concern."	Annual periods ending after December 15, 2016 (October 31, 2017 for us), and interim and annual periods thereafter; early adoption is permitted.	The adoption of this guidance will have no impact on our financial position, results of operations or cash flows. It will require establishing a going concern assessment process to meet the standard.
	ASU 2015-01, January 2015, Income Statement - Extraordinary and Unusual Items (Subtopic 225-20)	The FASB issued accounting guidance eliminating the concept of extraordinary items, thus eliminating the need to assess whether a particular event or transaction event is extraordinary. The presentation and disclosure guidance for items that are unusual in nature or occur infrequently will be retained and will be expanded to include items that are both unusual in nature and infrequently occurring, with the amendments being applicable either prospectively or retrospectively, to all prior periods presented in the financial statements.	Annual periods beginning after December 15, 2015 (November 1, 2016 for us), and interim periods within those periods, with early adoption permitted, provided that the guidance is applied from the beginning of the fiscal year of adoption.	The adoption of this guidance will be applied on a prospective basis. We have not had any extraordinary or unusual items that would impact our financial position, results of operations or cash flows.
	ASU 2015-02, February 2015, Consolidation - Amendments to the Consolidation Analysis (Topic 810)	The FASB issued accounting guidance which amends the consolidation requirements in ASC 810. The amendments significantly changes the consolidation analysis required under U.S. GAAP. The focus of this guidance is largely on the investment management industry related to limited partnerships becoming variable interest entities; however, it could have an impact on the consolidation conclusions of reporting entities in other industries.	Annual periods beginning after December 15, 2015 (November 1, 2016 for us), and interim periods within those periods, with early adoption permitted, provided that the guidance is applied from the beginning of the annual period containing the adoption date.	The adoption of this guidance will have no impact on our financial position, results of operations or cash flows.
	ASU 2015-03, April 2015, Interest: Imputation of Interest - Simplifying the Presentation of Debt Issuance Costs(Subtopic 835-30)	The FASB issued accounting guidance as part of its simplification initiative to reduce complexity in accounting standards. The amendment requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by this amendment.	Annual periods beginning after December 15, 2015 (November 1, 2016 for us), and interim periods within those fiscal years, with early adoption permitted for financial statements that have not been previously issued.	The adoption of this guidance will have no effect on the results of operations or cash flows. It will retrospectively affect the presentation of the balance sheet line items current and noncurrent "Regulatory assets," "Long-term debt" and "Short-term debt."
	ASU 2015-05, April 2015, Intangibles -Goodwill and Other - Internal-Use Software: Customer's Accounting for Fees Paid in a Cloud Computing Arrangement (Subtopic 350-40)	The FASB issued accounting guidance that amends ASC 350-40 to provide customers with guidance on determining whether a cloud computing arrangement contains a software license that should be accounted for as internal-use software. The guidance applies only to hosting arrangements if both of the following criteria are met: (a) the customer has the contractual right to take possession of the software at any time during the hosting period without significant penalty and (b) it is feasible for the customer to run the software on its own hardware or contract with another party to host the software.	Annual periods (and interim periods therein) beginning after December 15, 2015 (November 1, 2016 for us), with early adoption permitted. Entities may adopt the guidance (1) retrospectively or (2) prospectively to arrangements entered into, or materially modified, after the effective date.	We are currently evaluating the effect on our financial position, results of operations and cash flows.
	ASU 2015-07, May 2015, Fair Value Measurement: Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent) (Topic 820)	The FASB issued accounting guidance that amends the required disclosure of	Annual periods beginning after December 15, 2015 (November 1, 2016 for us), and interim periods within those fiscal years, with retrospective application to all periods presented and early adoption permitted.	The adoption of this guidance will have no impact on our financial position, results of operations or cash flows. We will present certain benefit plan assets under the new guidance.
		investments for which fair value is measured at net asset value per share (or its equivalent). The amendments remove the requirement to make certain disclosures for all investments that are eligible to be measured at fair value using the net asset value per share practical expedient.

Regulatory_Matters_Regulatory_

Regulatory Matters Regulatory Matters (Tables)	6 Months Ended
	Apr. 30, 2015
Regulated Operations [Abstract]
Schedule of Regulatory Assets
	In thousands	April 30,		October 31,
		2015		2014
	Regulatory Assets:
	Current:
	Unamortized debt expense	$	1,516	$	1,490
	Amounts due from customers	—		16,108
	Environmental costs	1,541		1,568
	Deferred operations and maintenance expenses	916		916
	Deferred pipeline integrity expenses	3,470		3,470
	Deferred pension and other retirement benefit costs	2,757		2,769
	Robeson liquefied natural gas (LNG) development costs	649		917
	Other	688		1,850
	Total current	11,537		29,088
	Noncurrent:
	Unamortized debt expense	14,632		15,402
	Environmental costs	5,735		6,470
	Deferred operations and maintenance expenses	4,331		4,721
	Deferred pipeline integrity expenses	26,024		24,694
	Deferred pension and other retirement benefit costs	19,239		18,799
	Amounts not yet recognized as a component of pension and other retirement benefit costs	91,088		94,265
	Regulatory cost of removal asset	18,649		18,275
	Robeson LNG development costs	318		509
	Other	1,424		1,644
	Total noncurrent	181,440		184,779
	Total	$	192,977	$	213,867
Schedule of Regulatory Liabilities
	Regulatory Liabilities:
	Current:
	Amounts due to customers	$	61,498	$	46,231
	Noncurrent:
	Regulatory cost of removal obligations	515,168		506,574
	Deferred income taxes	54,656		51,930
	Amounts not yet recognized as a component of pension and other retirement benefit costs	89		94
	Total noncurrent	569,913		558,598
	Total	$	631,411	$	604,829

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	6 Months Ended
	Apr. 30, 2015
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	A reconciliation of basic and diluted EPS, which includes contingently issuable shares that could affect EPS if performance units ultimately vest and the FSA settles in shares, for the three months and six months ended April 30, 2015 and 2014 is presented below.
		Three Months				Six Months
	In thousands, except per share amounts	2015		2014		2015		2014
	Net Income	$	66,402	$	62,540	$	159,380	$	160,112
	Average shares of common stock outstanding for basic earnings per share	78,818		77,982		78,717		77,477
	Contingently issuable shares under incentive compensation plans	279		309		302		325
	Contingently issuable shares under forward sale agreement	18				29
	Average shares of dilutive stock	79,115		78,291		79,048		77,802
	Earnings Per Share of Common Stock:
	Basic	$	0.84	$	0.8	$	2.02	$	2.07
	Diluted	$	0.84	$	0.8	$	2.02	$	2.06

Short_Term_Debt_Instruments_Ta

Short Term Debt Instruments (Tables)	6 Months Ended
	Apr. 30, 2015
Line of Credit Facility [Abstract]
Schedule of Line of Credit Facilities	We did not have any borrowings under the revolving syndicated credit facility for the six months ended April 30, 2015. A summary of the short-term debt activity under our CP program for the three months and six months ended April 30, 2015 is as follows.
	In millions	Three Months			Six Months
	Minimum amount outstanding during period	$	230		$	230
	Maximum amount outstanding during period	$	480		$	580
	Minimum interest rate during period	0.16		%	0.15		%
	Maximum interest rate during period	0.23		%	0.3		%
	Weighted average interest rate during period	0.21		%	0.21		%

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	6 Months Ended
	Apr. 30, 2015
Stockholders' Equity Note [Abstract]
Schedule Of Capital Stock	Changes in common stock for the six months ended April 30, 2015 are as follows.
	In thousands	Shares			Amount
	Balance, October 31, 2014	78,531			$	636,835
	Issued to participants in the Employee Stock Purchase Plan (ESPP)	16			612
	Issued to participants in the Dividend Reinvestment and Stock Purchase Plan	307			11,276
	Issued to participants in the Incentive Compensation Plan (ICP)	129			4,887
	Costs from issuance of common stock				(358		)
	Balance, April 30, 2015	78,983			$	653,252
Dividends Declared	Cash dividends paid per share of common stock for the three months and six months ended April 30, 2015 and 2014 are as follows.
		Three Months							Six Months
		2015				2014			2015			2014
	Cash dividends paid per share of common stock	$	0.33			$	0.32		$	0.65		$	0.63
Schedule Of Accumulated Other Comprehensive Income (Loss)	Changes in each component of accumulated OCIL are presented below for the three months and six months ended April 30, 2015 and 2014.
		Changes in Accumulated OCIL(1)
		Three Months							Six Months
	In thousands	2015				2014			2015			2014
	Accumulated OCIL beginning balance, net of tax	$	(1,064	)		$	27		$	(237	)	$	(284	)
	Hedging activities of equity method investments:
	OCIL before reclassifications, net of tax	(316		)		352			(1,260		)	526
	Amounts reclassified from accumulated OCIL, net of tax	449				(359		)	566			(222		)
	Total current period activity of hedging activities of equity method investments, net of tax	133				(7		)	(694		)	304
	Net current period benefit activities of equity method investments, net of tax	(39		)					(39		)
	Accumulated OCIL ending balance, net of tax	$	(970	)		$	20		$	(970	)	$	20
	(1) Amounts in parentheses indicate debits to accumulated OCIL.
Reclassification Out Of Accumulated Other Comprehensive Income	A reconciliation of the effect on certain line items of net income on amounts reclassified out of each component of accumulated OCIL is presented below for the three months and six months ended April 30, 2015 and 2014.
		Reclassification Out of Accumulated OCIL (1)													Affected Line Items on Condensed
		Three Months							Six Months						Statements of Operations and Comprehensive Income
	In thousands	2015				2014			2015			2014
	Hedging activities of equity method investments	$	735			$	587		$	927		$	362		Income from equity method investments
	Income tax expense	(286		)		(228		)	(361		)	(140		)	Income taxes
	Hedging activities of equity method investments	449				359			566			222
	Net benefit activities of equity method investments	(64		)					(64		)				Income from equity method investments
	Income tax expense	25							25						Income taxes
	Net benefit activities of equity method investments	(39		)					(39		)
	Total reclassification for the period, net of tax	$	410			$	359		$	527		$	222
	(1) Amounts in parentheses indicate debits to accumulated OCIL.

Marketable_Securities_Tables

Marketable Securities (Tables)	6 Months Ended
	Apr. 30, 2015
Marketable Securities [Abstract]
Marketable Securities Table	The composition of these securities as of April 30, 2015 and October 31, 2014 is as follows.
		30-Apr-15				31-Oct-14
	In thousands	Cost		Fair		Cost		Fair
				Value				Value
	Current trading securities:
	Money markets	$	47	$	47	$	22	$	22
	Mutual funds	121		201		106		192
	Total current trading securities	168		248		128		214
	Noncurrent trading securities:
	Money markets	484		484		447		447
	Mutual funds	3,563		4,221		2,598		3,280
	Total noncurrent trading securities	4,047		4,705		3,045		3,727
	Total trading securities	$	4,215	$	4,953	$	3,173	$	3,941

Financial_Instruments_Related_1

Financial Instruments & Related Fair Value (Tables)	6 Months Ended
	Apr. 30, 2015
Financial Instruments And Related Fair Value [Abstract]
Assets And Liabilities Measured And Recorded At Fair Value On Recurring Basis	The following table sets forth, by level of the fair value hierarchy, our financial assets that were accounted for at fair value on a recurring basis as of April 30, 2015 and October 31, 2014.
	Recurring Fair Value Measurements as of April 30, 2015
	In thousands	Quoted Prices			Significant		Significant			Effects of		Total
		in Active			Other		Unobservable			Netting and		Carrying
		Markets			Observable		Inputs			Cash Collateral		Value
		(Level 1)			Inputs		(Level 3)			Receivables /
					(Level 2)					Payables
	Assets:
	Derivatives held for utility operations	$	2,142		$	—	$	—		$	—	$	2,142
	Debt and equity securities held as trading securities:
	Money markets	531			—		—			—		531
	Mutual funds	4,422			—		—			—		4,422
	Total fair value assets	$	7,095		$	—	$	—		$	—	$	7,095
	Recurring Fair Value Measurements as of October 31, 2014
	In thousands	Quoted Prices			Significant		Significant			Effects of		Total
		in Active			Other		Unobservable			Netting and		Carrying
		Markets			Observable		Inputs			Cash Collateral		Value
		(Level 1)			Inputs		(Level 3)			Receivables /
					(Level 2)					Payables
	Assets:
	Derivatives held for utility operations	$	4,898		$	—	$	—		$	—	$	4,898
	Debt and equity securities held as trading securities:
	Money markets	469			—		—			—		469
	Mutual funds	3,472			—		—			—		3,472
	Total fair value assets	$	8,839		$	—	$	—		$	—	$	8,839
Fair Value By Balance Sheet Grouping	The carrying amount and fair value of our long-term debt, including the current portion, which is classified within Level 2, are shown below.
	In thousands	Carrying			Fair Value
		Amount  (1)
	As of April 30, 2015	$	1,425,000		$	1,634,164
	As of October 31, 2014	1,425,000			1,617,453
	(1) Excludes discount on issuance of notes of $557 and $570 as of April 30, 2015 and October 31, 2014, respectively.
Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]	The following table presents the impact that financial instruments not designated as hedging instruments under derivative accounting standards would have had on the Condensed Consolidated Statements of Comprehensive Income for the three months and six months ended April 30, 2015 and 2014, absent the regulatory treatment under our approved PGA procedures.
		Amount of Gain (Loss) Recognized										Location of Gain (Loss)
		on Derivative Instruments and Deferred Under PGA Procedures										Recognized through
												PGA Procedures
		Three Months Ended					Six Months Ended
		April 30					April 30
	In thousands	2015			2014		2015			2014
	Gas purchase options	$	(1,731	)	$	3,297	$	(2,289	)	$	7,826	Cost of Gas
	The following table presents the fair value and balance sheet classification of our financial options for natural gas as of April 30, 2015 and October 31, 2014.
	Fair Value of Derivative Instruments
		April 30,			October 31,
	In thousands	2015			2014
	Derivatives Not Designated as Hedging Instruments under Derivative Accounting Standards:
	Asset Financial Instruments:
	Current Assets – Gas purchase derivative assets (June 2015 - May 2016)	$	2,142
	Current Assets – Gas purchase derivative assets (December 2014 - November 2015)				$	4,898

Employee_Benefit_Plans_Tables

Employee Benefit Plans (Tables)	6 Months Ended
	Apr. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Components Of Net Periodic Benefit Cost	Components of the net periodic benefit cost for our defined benefit pension plans and our other postretirement employee benefits (OPEB) plan for the three months ended April 30, 2015 and 2014 are presented below.
		Qualified Pension						Nonqualified				Other Benefits
								Pension
	In thousands	2015			2014			2015		2014		2015			2014
	Service cost	$	3,050		$	2,750		$	—	$	—	$	295		$	277
	Interest cost	2,975			2,950			52		45		369			362
	Expected return on plan assets	(5,925		)	(5,700		)	—		—		(459		)	(457		)
	Amortization of prior service (credit) cost	(550		)	(550		)	58		20		—			—
	Amortization of actuarial loss	2,050			1,875			21		12		7			—
	Total	$	1,600		$	1,325		$	131	$	77	$	212		$	182
	Components of the net periodic benefit cost for our defined benefit pension plans and our OPEB plan for the six months ended April 30, 2015 and 2014 are presented below.
		Qualified Pension						Nonqualified				Other Benefits
								Pension
	In thousands	2015			2014			2015		2014		2015			2014
	Service cost	$	6,100		$	5,500		$	—	$	—	$	591		$	554
	Interest cost	5,950			5,900			104		90		738			724
	Expected return on plan assets	(11,850		)	(11,400		)	—		—		(919		)	(915		)
	Amortization of prior service (credit) cost	(1,100		)	(1,100		)	115		41		—			—
	Amortization of actuarial loss	4,100			3,750			43		23		15			—
	Total	$	3,200		$	2,650		$	262	$	154	$	425		$	363
Anticipated Employer Contribution To Benefit Plans	We anticipate that we will contribute the following additional amounts to our plans in 2015.
	In thousands
	Nonqualified pension plans	$	282
	OPEB plan	1,500

Employee_ShareBased_Plans_Tabl

Employee Share-Based Plans (Tables)	6 Months Ended
	Apr. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Compensation Expense And Liabilities	The compensation expense related to the incentive compensation plans for the three months and six months ended April 30, 2015 and 2014, and the amounts recorded as liabilities in “Other noncurrent liabilities” in “Noncurrent Liabilities” with the current portion recorded in “Other current liabilities” in “Current Liabilities” in the Condensed Consolidated Balance Sheets as of April 30, 2015 and October 31, 2014 are presented below.
		Three Months				Six Months
	In thousands	2015		2014		2015		2014
	Compensation expense	$	1,050	$	2,103	$	3,279	$	4,203
		April 30,		October 31,
		2015		2014
	Liability	$	11,143	$	15,130

Equity_Method_Investments_Tabl

Equity Method Investments (Tables)	6 Months Ended
	Apr. 30, 2015
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Equity Method Investments	We have the following membership interests in these companies as of April 30, 2015 and October 31, 2014, respectively.
	Equity Method Investment	Interest			Activity
	Atlantic Coast Pipeline, LLC (ACP)	10	%		To develop, construct, own and operate approximately 550 miles of interstate natural gas pipeline with associated compression from West Virginia through Virginia into eastern North Carolina in order to provide interstate natural gas transportation services of Marcellus and Utica gas supplies into southeastern markets; regulated by the FERC
	Cardinal Pipeline Company, L.L.C (Cardinal)	21.49	%		Intrastate pipeline located in North Carolina; regulated by the NCUC
	Constitution Pipeline Company LLC (Constitution)	24	%		To develop, construct, own and operate approximately 120 miles of interstate natural gas pipeline, and related facilities, connecting shale natural gas supplies and gathering systems in Susquehanna County, Pennsylvania, to Iroquois Gas Transmission and Tennessee Gas Pipeline systems in New York; regulated by the FERC
	Hardy Storage Company (Hardy Storage)	50	%		Underground interstate storage facility located in Hardy and Hampshire Counties, West Virginia; regulated by the FERC
	Pine Needle LNG Company, L.L.C. (Pine Needle)	45	%		Interstate LNG storage facility located in North Carolina; regulated by the FERC
	SouthStar	15	%		Energy services company primarily selling natural gas in the unregulated retail gas market to residential, commercial and industrial customers in the eastern United States, primarily Georgia and Illinois
	For each period of the three months and six months ended April 30, 2015 and 2014, our operating revenues from these sales and the amounts SouthStar owed us as of April 30, 2015 and October 31, 2014 are as follows.
		Operating Revenues (1)																Trade accounts receivable (2)
		Three Months								Six Months								April 30,				October 31,
	In thousands	2015				2014				2015				2014				2015				2014
	Operating revenues	$	187			$	475			$	583			$	907			$	177			$	460
	(1) In the Condensed Consolidated Statements of Comprehensive Income.
	(2) In the Condensed Consolidated Balance Sheets.
	For each period of the three months and six months ended April 30, 2015 and 2014, these gas costs and the amounts we owed to our equity method investees, as of April 30, 2015 and October 31, 2014 are as follows.
	Related Party	Type of Expense		Cost of Gas (1)																Trade accounts payable (2)
				Three Months								Six Months								April 30,				October 31,
	In thousands			2015				2014				2015				2014				2015				2014
	Cardinal	Transportation costs		$	2,135			$	2,164			$	4,349			$	4,404			$	720			$	747
	Hardy Storage	Gas storage costs		2,322				2,392				4,645				4,817				774				774
	Pine Needle	Gas storage costs		2,840				2,701				5,776				5,494				957				989
	Totals			$	7,297			$	7,257			$	14,770			$	14,715			$	2,451			$	2,510
	(1) In the Condensed Consolidated Statements of Comprehensive Income.
	(2) In the Condensed Consolidated Balance Sheets.

Variable_Interest_Entities_Tab

Variable Interest Entities (Tables)	6 Months Ended
	Apr. 30, 2015
Variable Interest Entity, Not Primary Beneficiary, Disclosures [Abstract]
Schedule Of Variable Interest Entities Investment Balances	As of April 30, 2015 and October 31, 2014, our investment balances are as follows.
	In thousands	April 30,		October 31,
		2015		2014
	Cardinal	$	15,501	$	16,073
	Pine Needle	18,237		18,689
	SouthStar	38,396		40,965
	Hardy Storage	38,738		37,179
	Constitution	69,784		57,255
	ACP	5,335		10
	Total equity method investments in non-utility activities	$	185,991	$	170,171

Business_Segments_Tables

Business Segments (Tables)	6 Months Ended
	Apr. 30, 2015
Segment Reporting [Abstract]
Operations By Segment	Operations by segment for the three months and six months ended April 30, 2015 and 2014 are presented below.
		Regulated Utility						Regulated						Unregulated						Total
								Non-Utility						Non-Utility
								Activities						Activities
	In thousands	2015			2014			2015			2014			2015			2014			2015		2014
	Three Months
	Revenues from external customers	$	424,924		$	462,247		$	—		$	—		$	—		$	—		$	424,924	$	462,247
	Margin	225,621			211,523			—			—			—			—			225,621		211,523
	Operations and maintenance expenses	71,424			70,193			20			8			9			13			71,453		70,214
	Income from equity method investments	—			—			3,577			2,467			12,265			11,893			15,842		14,360
	Operating income (loss) before income taxes	111,532			103,489			(20		)	(8		)	(14		)	(17		)	111,498		103,464
	Income before income taxes	92,918			88,999			3,557			2,459			12,252			11,876			108,727		103,334
	Six Months
	Revenues from external customers	$	1,032,196		$	1,119,980		$	—		$	—		$	—		$	—		$	1,032,196	$	1,119,980
	Margin	495,691			473,035			—			—			—			—			495,691		473,035
	Operations and maintenance expenses	137,574			130,832			51			14			47			32			137,672		130,878
	Income from equity method investments	—			—			7,348			5,574			16,759			18,728			24,107		24,302
	Operating income (loss) before income taxes	273,562			265,610			(51		)	(14		)	(135		)	(119		)	273,376		265,477
	Income before income taxes	237,318			240,268			7,297			5,560			16,625			18,608			261,240		264,436
Reconciliation of Operating Profit (Loss) from Segments to Consolidated	Reconciliations to the condensed consolidated statements of comprehensive income for the three months and six months ended April 30, 2015 and 2014 are presented below.
		Three Months						Six Months
	In thousands	2015			2014			2015			2014
	Operating Income:
	Segment operating income before income taxes	$	111,498		$	103,464		$	273,376		$	265,477
	Utility income taxes	(36,409		)	(36,190		)	(92,680		)	(95,992		)
	Regulated non-utility activities operating loss before income taxes	20			8			51			14
	Unregulated non-utility activities operating loss before income taxes	14			17			135			119
	Operating income	$	75,123		$	67,299		$	180,882		$	169,618
	Net Income:
	Income before income taxes for reportable segments	$	108,727		$	103,334		$	261,240		$	264,436
	Income taxes	(42,325		)	(40,794		)	(101,860		)	(104,324		)
	Total	$	66,402		$	62,540		$	159,380		$	160,112

Regulatory_Matters_Assets_and_

Regulatory Matters - Assets and Liabilities (Details) (USD $)	Apr. 30, 2015	Oct. 31, 2014
In Thousands, unless otherwise specified
Regulatory Liabilities [Line Items]
Regulatory liabilities - current	$61,498	$46,231
Regulatory liabilities - noncurrent	569,913	558,598
Regulatory liabilities, Total	631,411	604,829
Regulatory Assets [Line Items]
Regulatory assets - current	11,537	29,088
Regulatory assets - noncurrent	181,440	184,779
Regulatory assets, Total	192,977	213,867
Unamortized debt expense
Regulatory Assets [Line Items]
Regulatory assets - current	1,516	1,490
Regulatory assets - noncurrent	14,632	15,402
Amounts due from customers
Regulatory Assets [Line Items]
Regulatory assets - current	0	16,108
Environmental costs
Regulatory Assets [Line Items]
Regulatory assets - current	1,541	1,568
Regulatory assets - noncurrent	5,735	6,470
Deferred operations and maintenance expenses
Regulatory Assets [Line Items]
Regulatory assets - current	916	916
Regulatory assets - noncurrent	4,331	4,721
Deferred pipeline integrity expenses
Regulatory Assets [Line Items]
Regulatory assets - current	3,470	3,470
Regulatory assets - noncurrent	26,024	24,694
Deferred pension and other retirement benefit costs
Regulatory Assets [Line Items]
Regulatory assets - current	2,757	2,769
Regulatory assets - noncurrent	19,239	18,799
Amounts not yet recognized as a component of pension and other retirement benefit costs
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	91,088	94,265
Regulatory cost of removal
Regulatory Assets [Line Items]
Regulatory assets - noncurrent	18,649	18,275
Robeson liquefied natural gas (LNG) development costs
Regulatory Assets [Line Items]
Regulatory assets - current	649	917
Regulatory assets - noncurrent	318	509
Other
Regulatory Assets [Line Items]
Regulatory assets - current	688	1,850
Regulatory assets - noncurrent	1,424	1,644
Amounts due to customers
Regulatory Liabilities [Line Items]
Regulatory liabilities - current	61,498	46,231
Regulatory cost of removal
Regulatory Liabilities [Line Items]
Regulatory liabilities - noncurrent	515,168	506,574
Deferred income taxes
Regulatory Liabilities [Line Items]
Regulatory liabilities - noncurrent	54,656	51,930
Amounts not yet recognized as a component of pension and other retirement benefit costs
Regulatory Liabilities [Line Items]
Regulatory liabilities - noncurrent	$89	$94

Regulatory_Matters_Rate_and_Re

Regulatory Matters - Rate and Regulatory Actions (Details) (USD $)	6 Months Ended		12 Months Ended
	Apr. 30, 2015	Apr. 30, 2014	Oct. 31, 2014
Public Utilities, Rate Matters, Approved [Abstract]
Increase (Decrease) In Regulatory liabilities	$17,987,000	$78,791,000
NORTH CAROLINA
Public Utilities, General Disclosures [Line Items]
Capital Investments In Integrity and Safety Projects			241,900,000
TENNESSEE
Public Utilities, General Disclosures [Line Items]
Capital Investments In Integrity and Safety Projects			54,000,000
North Carolina Utilities Commission | NCUC Authorized IMR Adjustment January 2015
Public Utilities, Rate Matters, Approved [Abstract]
Public Utilities Approved Rate Increase (Decrease) Amount	26,600,000
North Carolina Utilities Commission | NCUC Approved Customer Bill Credit March 2015 | Amounts due to customers
Public Utilities, Rate Matters, Approved [Abstract]
Increase (Decrease) In Regulatory liabilities	-45,000,000
Tennessee Regulatory Authority | Amortization And Refund For Excess Deferred Taxes
Public Utilities, Rate Matters, Requested [Abstract]
Public Utilities Requested Rate Increase (Decrease) Amount	-4,700,000
Proposed Amortization Time Period For Specified Expenses	3 years
Tennessee Regulatory Authority | TRA Approved IMR Adjustment February 2015
Public Utilities, Rate Matters, Approved [Abstract]
Public Utilities Approved Rate Increase (Decrease) Amount	6,500,000
Tennessee Regulatory Authority | Tennessee Ruling Compressed Natural Gas February 2015
Public Utilities, Rate Matters, Approved [Abstract]
Deferral CNG Equipment In Utility Rate Base	$4,700,000

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2015	Apr. 30, 2014
Earnings Per Share [Abstract]
Net Income	$66,402	$62,540	$159,380	$160,112
Average shares of common stock outstanding for basic earnings per share	78,818	77,982	78,717	77,477
Contingently issuable shares under incentive compensation plans	279	309	302	325
Contingently issuable shares under forward sale agreement	18		29
Average shares of dilutive stock	79,115	78,291	79,048	77,802
Basic (usd per share)	$0.84	$0.80	$2.02	$2.07
Diluted (usd per share)	$0.84	$0.80	$2.02	$2.06

Longterm_Debt_Instruments_Deta

Long-term Debt Instruments (Details) (North Carolina Utilities Commission, USD $)	6 Months Ended
	Apr. 30, 2015
North Carolina Utilities Commission
Debt Instrument [Line Items]
Public Utilities, Approved Debt Equity Securities Limit, Amount	$1,000,000,000
Debt and Equity Shelf Registration, Term	3 years
Public Utilities, Approved Debt Equity Securities Limit, Amount Remaining	$750,000,000

Short_Term_Debt_Instruments_De

Short Term Debt Instruments (Details) (USD $)	3 Months Ended	6 Months Ended
	Apr. 30, 2015	Apr. 30, 2015	Oct. 31, 2014
Line Of Credit Facility [Line Items]
Credit Facility Current Borrowing Capacity	$850,000,000	$850,000,000
Maximum Facility	850,000,000	850,000,000
Commercial Paper	255,000,000	255,000,000	355,000,000
Revolving Credit Facility
Line Of Credit Facility [Line Items]
Credit Facility Current Borrowing Capacity	850,000,000	850,000,000
Line of Credit Facility, Expiration Date		1-Oct-17
Line Of Credit Facility Frequency Of Commitment Fee Payment		annual
Line of Credit Facility, Commitment Fee Description		$35,000 plus 8.5 basis points
Credit Facility Interest Rate Description		30-day London Interbank Offered Rate (LIBOR) plus from 75 to 125 basis points
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage		0.09%
Line of Credit Facility, Commitment Fee Amount		35,000
Credit Facility Covenant Terms		total debt to total capitalization of no greater than 70%
Credit Facility Covenant Compliance		actual ratio was 54%
Debt Covenant Total Debt To Total Capital Ratio		70.00%
Ratio of Indebtedness to Net Capital	0.54	0.54
Revolving Credit Facility | Minimum | London Interbank Offered Rate (LIBOR)
Line Of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		0.75%
Revolving Credit Facility | Maximum | London Interbank Offered Rate (LIBOR)
Line Of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.25%
Letter Of Credit
Line Of Credit Facility [Line Items]
Credit Facility Current Borrowing Capacity	10,000,000	10,000,000	10,000,000
Letters of Credit Outstanding, Amount	1,700,000	1,700,000	1,800,000
Commercial Paper
Line Of Credit Facility [Line Items]
Credit Facility Interest Rate Description		interest based on, among other things, the size and maturity date of the note, the frequency of the issuance and our credit ratings, plus a spread of 5 basis points
Short Term Borrowings Term		$850 million unsecured CP program that is backstopped by the revolving syndicated credit facility. The amounts outstanding under the revolving syndicated credit facility and the CP program, either individually or in the aggregate, cannot exceed $850 million. The notes issued under the CP program may have maturities not to exceed 397 days from the date of issuance and bear interest based on, among other things, the size and maturity date of the note, the frequency of the issuance and our credit ratings, plus a spread of 5 basis points. Any borrowings under the CP program rank equally with our other unsecured debt.
Maximum Number Of Possible Days Outstanding For Commercial Paper Program		397 days
Commercial Paper	255,000,000	255,000,000	355,000,000
Weighted Average Interest Rate	0.21%	0.21%	0.17%
Minimum amount outstanding during period	230,000,000	230,000,000
Maximum amount outstanding during period	$480,000,000	$580,000,000
Commercial Paper | Base Rate
Line Of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		0.05%
Commercial Paper | Minimum
Line Of Credit Facility [Line Items]
Debt Instrument, Term	4 days
Line of Credit Facility Interest Rate During Period	0.16%	0.15%
Commercial Paper | Maximum
Line Of Credit Facility [Line Items]
Debt Instrument, Term	14 days
Line of Credit Facility Interest Rate During Period	0.23%	0.30%
Commercial Paper | Weighted Average
Line Of Credit Facility [Line Items]
Line of Credit Facility Interest Rate During Period	0.21%	0.21%

Stockholders_Equity_Details

Stockholders' Equity (Details) (USD $)	0 Months Ended	1 Months Ended	3 Months Ended		6 Months Ended
	Jan. 07, 2015	Apr. 24, 2015	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2015	Apr. 30, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Outstanding, Beginning Balance					78,531,000
Common Stock, Value, Issued, Beginning Balance					$636,835,000
Issued to participants in the Employee Stock Purchase Plan (ESPP) (in shares)					16,000
Issued to participants in the Employee Stock Purchase Plan (ESPP)					612,000
Issued to participants in the Dividend Reinvestment and Stock Purchase Plan (in shares)					307,000
Issued to participants in the Dividend Reinvestment and Stock Purchase Plan					11,276,000
Issued to participants in the Incentive Compensation Plan (ICP) (in shares)					129,000
Issued to participants in the Incentive Compensation Plan (ICP)					4,887,000
Costs from issuance of common stock					-358,000	-12,000
Common Stock, Shares, Outstanding, Ending Balance			78,983,000		78,983,000
Common Stock, Value, Issued, Ending Balance			653,252,000		653,252,000
ATM Sales Agreement Aggregate Amount	170,000,000
ATM Sales Agreement Commission Percentage			1.50%
Cash dividends paid per share of common stock (usd per share)			$0.33	$0.32	$0.65	$0.63
Forward Contract Indexed to Issuer's Equity [Line Items]
Forward Contract Indexed to Issuer's Equity, Shares		612,000
Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share		$36.83
Initial Forward Price Per Share		$36.28
Forward Contract Indexed to Issuer's Equity, Settlement Alternatives					Under the terms of this FSA, at our election, we may physically settle in shares, cash or net settle for all or a portion of our obligation under the agreement.
Forward Contract Indexed to Issuer's Equity, Settlement Date					31-Oct-15
Forward Contract Indexed to Issuer's Equity, Classification					we have classified the FSA as equity transactions because the forward sale transactions are indexed to our own stock and physical settlement is within our control
Forward Contract Amount Recorded in Consolidated Financial Statements			0		0
Forward Contract Indexed to Issuer's Equity, Indexed Shares			612,000		612,000
Forward Contract Indexed to Issuer's Equity, Settlement Alternatives, Cash, at Fair Value			22,200,000		22,200,000
Net Settlement Price Per Share			$36.27		$36.27
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from equity method investments			15,842,000	14,360,000	24,107,000	24,302,000
Income taxes			-5,916,000	-4,604,000	-9,180,000	-8,332,000
Net income			66,402,000	62,540,000	159,380,000	160,112,000
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated OCIL beginning balance, net of tax			-1,064,000	27,000	-237,000	-284,000
Total other comprehensive income (loss)			94,000	-7,000	-733,000	304,000
Accumulated OCIL ending balance, net of tax			-970,000	20,000	-970,000	20,000
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income			410,000	359,000	527,000	222,000
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
OCIL before reclassifications, net of tax			-316,000	352,000	-1,260,000	526,000
Amounts reclassified from accumulated OCIL, net of tax			449,000	-359,000	566,000	-222,000
Total other comprehensive income (loss)			133,000	-7,000	-694,000	304,000
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from equity method investments			735,000	587,000	927,000	362,000
Income taxes			-286,000	-228,000	-361,000	-140,000
Net income			449,000	359,000	566,000	222,000
Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Total other comprehensive income (loss)			-39,000		-39,000
Accumulated Defined Benefit Plans Adjustment | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from equity method investments			-64,000		-64,000
Income taxes			25,000		25,000
Net income			($39,000)		($39,000)
Maximum
Forward Contract Indexed to Issuer's Equity [Line Items]
Forward Contract Indexed to Issuer's Equity, Settlement Date					15-Dec-15

Marketable_Securities_Details

Marketable Securities (Details) (USD $)	Apr. 30, 2015	Oct. 31, 2014
In Thousands, unless otherwise specified
Investment Measurement [Line Items]
Current trading securities (cost)	$168	$128
Noncurrent trading securities (cost)	4,047	3,045
Current trading securities (fair value)	248	214
Noncurrent trading securities (fair value)	4,705	3,727
Total trading securities (cost)	4,215	3,173
Total trading (fair value)	4,953	3,941
Money markets
Investment Measurement [Line Items]
Current trading securities (cost)	47	22
Noncurrent trading securities (cost)	484	447
Current trading securities (fair value)	47	22
Noncurrent trading securities (fair value)	484	447
Mutual funds
Investment Measurement [Line Items]
Current trading securities (cost)	121	106
Noncurrent trading securities (cost)	3,563	2,598
Current trading securities (fair value)	201	192
Noncurrent trading securities (fair value)	$4,221	$3,280

Financial_Instruments_Related_2

Financial Instruments & Related Fair Value (Details) (USD $)	3 Months Ended		6 Months Ended
	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2015	Apr. 30, 2014	Oct. 31, 2014
	MMBTU		MMBTU		MMBTU
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long gas purchase options providing total coverage	32,700,000		32,700,000		29,200,000
Fair value measurement transfers between levels activity	$0	$0
Derivative Liability	0		0		0
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0		0		0
Derivative Asset, Collateral, Obligation to Return Cash, Offset	0		0		0
ASSETS
Debt and equity securities held as trading securities	4,953,000		4,953,000		3,941,000
Long-term debt, carry amount	1,425,000,000		1,425,000,000		1,425,000,000
Long-term debt, fair value	1,634,164,000		1,634,164,000		1,617,453,000
Discount on issuance of notes	557,000		557,000		570,000
Current Assets, Gas purchase derivative assets	2,142,000		2,142,000		4,898,000
Gas purchase options	-1,731,000	3,297,000	-2,289,000	7,826,000
Amount Of Gain (Loss) Deferred Under PGA Procedures	-1,731,000	3,297,000	-2,289,000	7,826,000
Percentage of annual gas costs approved for recovery under TIP			1.00%
Concentration Risk [Line Items]
Concentration risk, description			“Trade accounts receivable” in “Current Assets” in the Condensed Consolidated Balance Sheets
Accounts Receivable
Concentration Risk [Line Items]
Concentration risk amount	4,200,000		4,200,000
Accounts Receivable | Credit Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	5.00%
Fair Value, Measurements, Recurring
ASSETS
Derivatives held for utility operations	2,142,000		2,142,000		4,898,000
Total fair value assets	7,095,000		7,095,000		8,839,000
Money markets | Fair Value, Measurements, Recurring
ASSETS
Debt and equity securities held as trading securities	531,000		531,000		469,000
Mutual funds | Fair Value, Measurements, Recurring
ASSETS
Debt and equity securities held as trading securities	4,422,000		4,422,000		3,472,000
Quoted Prices in Active Markets (Level 1) | Fair Value, Measurements, Recurring
ASSETS
Derivatives held for utility operations	2,142,000		2,142,000		4,898,000
Total fair value assets	7,095,000		7,095,000		8,839,000
Quoted Prices in Active Markets (Level 1) | Money markets | Fair Value, Measurements, Recurring
ASSETS
Debt and equity securities held as trading securities	531,000		531,000		469,000
Quoted Prices in Active Markets (Level 1) | Mutual funds | Fair Value, Measurements, Recurring
ASSETS
Debt and equity securities held as trading securities	4,422,000		4,422,000		3,472,000
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
ASSETS
Derivatives held for utility operations	0		0		0
Total fair value assets	0		0		0
Significant Other Observable Inputs (Level 2) | Money markets | Fair Value, Measurements, Recurring
ASSETS
Debt and equity securities held as trading securities	0		0		0
Significant Other Observable Inputs (Level 2) | Mutual funds | Fair Value, Measurements, Recurring
ASSETS
Debt and equity securities held as trading securities	0		0		0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
ASSETS
Derivatives held for utility operations	0		0		0
Total fair value assets	0		0		0
Significant Unobservable Inputs (Level 3) | Money markets | Fair Value, Measurements, Recurring
ASSETS
Debt and equity securities held as trading securities	0		0		0
Significant Unobservable Inputs (Level 3) | Mutual funds | Fair Value, Measurements, Recurring
ASSETS
Debt and equity securities held as trading securities	$0		$0		$0

Commitments_and_Contingent_Lia1

Commitments and Contingent Liabilities (Details) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Apr. 30, 2015
Site Contingency [Line Items]
Accrual For Environmental Loss Contingencies Gross	1.1
Long-term Purchase Commitment [Line Items]
Number Of Regulatory Commissions	3
Pipeline And Storage Capacity Contacts | Maximum
Long-term Purchase Commitment [Line Items]
Long term purchase commitment time period	21 years
Gas Supply Contracts | Maximum
Long-term Purchase Commitment [Line Items]
Long term purchase commitment time period	2 years
Telecommunications And Technology Outsourcing Contracts | Maximum
Long-term Purchase Commitment [Line Items]
Long term purchase commitment time period	4 years
Letter Of Credit
Guarantor Obligations [Line Items]
Total contingent obligation	1.7
Surety Bond
Guarantor Obligations [Line Items]
Total contingent obligation	6.6

Employee_Benefit_Plans_Details

Employee Benefit Plans (Details) (USD $)	1 Months Ended		3 Months Ended		6 Months Ended
	Jan. 31, 2015	Nov. 30, 2014	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2015	Apr. 30, 2014
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Deferred Compensation Liability			$5,100,000		$5,100,000
Pension Plan | MPP Plan
Defined Contribution Plan Disclosure [Line Items]
Employer Contribution to Plan - defined contribution	1,400,000
Qualified Pension Plan
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost			3,050,000	2,750,000	6,100,000	5,500,000
Interest cost			2,975,000	2,950,000	5,950,000	5,900,000
Expected return on plan assets			-5,925,000	-5,700,000	-11,850,000	-11,400,000
Amortization of prior service (credit) cost			-550,000	-550,000	-1,100,000	-1,100,000
Amortization of actuarial loss			2,050,000	1,875,000	4,100,000	3,750,000
Total			1,600,000	1,325,000	3,200,000	2,650,000
Employer contribution amount - defined benefit		10,000,000
Non Qualified Pension
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost			0	0	0	0
Interest cost			52,000	45,000	104,000	90,000
Expected return on plan assets			0	0	0	0
Amortization of prior service (credit) cost			58,000	20,000	115,000	41,000
Amortization of actuarial loss			21,000	12,000	43,000	23,000
Total			131,000	77,000	262,000	154,000
Additional contribution amounts					282,000
Employer contribution amount - defined benefit					200,000
Other Postretirement Benefit Plan
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost			295,000	277,000	591,000	554,000
Interest cost			369,000	362,000	738,000	724,000
Expected return on plan assets			-459,000	-457,000	-919,000	-915,000
Amortization of prior service (credit) cost			0	0	0	0
Amortization of actuarial loss			7,000	0	15,000	0
Total			212,000	182,000	425,000	363,000
Additional contribution amounts					1,500,000
DCR Plan
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Employer Contribution to Plan - deferred compensation					500,000
Voluntary Deferral Plan
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Employer Contribution to Plan - deferred compensation					$0

Employee_ShareBased_Plans_Deta

Employee Share-Based Plans (Details) (USD $)	3 Months Ended		6 Months Ended		1 Months Ended	0 Months Ended
	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2015	Apr. 30, 2014	Dec. 31, 2011	Dec. 15, 2014	Oct. 31, 2014	Dec. 12, 2014
Employee Share Based Plans Details [Line Items]
Maximum allowable withholdings			50.00%
Compensation expense	$1,050,000	$2,103,000	$3,279,000	$4,203,000
Liability	11,143,000		11,143,000				15,130,000
ESPP exercise price as a percent			95.00%
Stock Compensation Plan
Employee Share Based Plans Details [Line Items]
Performance period			3 years
Retention Stock Unit Award President And Cheif Executive Officer | Stock Compensation Plan
Employee Share Based Plans Details [Line Items]
Retention stock unit award vesting period			5 years
Unvested Shares Issued To CEO					64,700
Incentive Compensation Plan Percentage Of Common Stock Vested			In accordance with the vesting schedule, 20% of the units vested on December 15, 2014, 30% of the units vest on December 15, 2015 and 50% of the units vest on December 15, 2016
Vested on December 15, 2014 | Retention Stock Unit Award President And Cheif Executive Officer | Stock Compensation Plan
Employee Share Based Plans Details [Line Items]
Common stock vesting percentage			20.00%
Stock Award Vested, Shares, Gross						14,461
Payments Related to Tax Withholding for Share-based Compensation						$300,000
Stock Issued During Period, Shares, Share-based Compensation, Gross						7,231
Share Price								$37.89
Vest on December 15, 2015 | Retention Stock Unit Award President And Cheif Executive Officer | Stock Compensation Plan
Employee Share Based Plans Details [Line Items]
Common stock vesting percentage			30.00%
Vest on December 15, 2016 | Retention Stock Unit Award President And Cheif Executive Officer | Stock Compensation Plan
Employee Share Based Plans Details [Line Items]
Common stock vesting percentage			50.00%

Equity_Method_Investments_Deta

Equity Method Investments (Details) (USD $)	3 Months Ended		6 Months Ended
	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2015	Apr. 30, 2014	Oct. 31, 2014
Schedule of Equity Method Investments [Line Items]
Related party costs	$7,297,000	$7,257,000	$14,770,000	$14,715,000
Trade accounts payable	2,451,000		2,451,000		2,510,000
Contributions to equity method investments			15,495,000	18,600,000
Atlantic Coast Pipeline
Schedule of Equity Method Investments [Line Items]
Membership interest percentage	10.00%		10.00%
Contributions to equity method investments	700,000		5,800,000
Target Pipeline In Service Date			2018
Long term purchase commitment time period			20 years
Estimated Percentage Project Financing			70.00%
Estimated Percentage Debt Financing			50.00%
Estimated Percentage Equity Financing			50.00%
Funding Obligation Under Equity Contribution Agreements			15,200,000
Cardinal Pipeline Company
Schedule of Equity Method Investments [Line Items]
Membership interest percentage	21.49%		21.49%
Related party costs	2,135,000	2,164,000	4,349,000	4,404,000
Trade accounts payable	720,000		720,000		747,000
Constitution Pipeline Company
Schedule of Equity Method Investments [Line Items]
Membership interest percentage	24.00%		24.00%
Estimated Pipeline Costs Including AFUDC	875,000,000		875,000,000
Estimated Pipeline Costs Excluding AFUDC	785,000,000		785,000,000
Contributions to equity method investments	4,800,000		9,700,000
Total equity contribution for the project	63,300,000		63,300,000
Target Pipeline In Service Date			2016
Hardy Storage
Schedule of Equity Method Investments [Line Items]
Membership interest percentage	50.00%		50.00%
Related party costs	2,322,000	2,392,000	4,645,000	4,817,000
Trade accounts payable	774,000		774,000		774,000
Pine Needle Company
Schedule of Equity Method Investments [Line Items]
Membership interest percentage	45.00%		45.00%
Related party costs	2,840,000	2,701,000	5,776,000	5,494,000
Trade accounts payable	957,000		957,000		989,000
South Star Energy Services
Schedule of Equity Method Investments [Line Items]
Membership interest percentage	15.00%		15.00%
Operating revenues	187,000	475,000	583,000	907,000
Trade accounts receivable	177,000		177,000		460,000
Minimum | Atlantic Coast Pipeline
Schedule of Equity Method Investments [Line Items]
Estimated Pipeline Development And Construction Costs	4,500,000,000		4,500,000,000
Estimated Contributions For Pipeline And Construction Costs	225,000,000		225,000,000
Maximum | Atlantic Coast Pipeline
Schedule of Equity Method Investments [Line Items]
Estimated Pipeline Development And Construction Costs	5,000,000,000		5,000,000,000
Estimated Contributions For Pipeline And Construction Costs	$250,000,000		$250,000,000

Variable_Interest_Entities_Det

Variable Interest Entities (Details) (Variable Interest Entity, Not Primary Beneficiary, USD $)	Apr. 30, 2015	Oct. 31, 2014
In Thousands, unless otherwise specified
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	$185,991	$170,171
Cardinal Pipeline Company
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	15,501	16,073
Pine Needle Company
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	18,237	18,689
South Star Energy Services
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	38,396	40,965
Hardy Storage
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	38,738	37,179
Constitution Pipeline Company
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	69,784	57,255
Atlantic Coast Pipeline
Variable Interest Entity [Line Items]
Total equity method investments in non-utility activities	$5,335	$10

Business_Segments_Details

Business Segments (Details) (USD $)	3 Months Ended				6 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2015		Apr. 30, 2014		Apr. 30, 2015	Apr. 30, 2014
					segment
Segment Reporting Information [Line Items]
Number of reportable segments					3
Segment Reporting Information [Abstract]
Revenues from external customers	$424,924	[1]	$462,247	[1]	$1,032,196	$1,119,980
Margin	225,621		211,523		495,691	473,035
Operations and maintenance expenses	71,453		70,214		137,672	130,878
Income from equity method investments	15,842		14,360		24,107	24,302
Operating income (loss) before income taxes	111,498		103,464		273,376	265,477
Income before income taxes for reportable segments	108,727		103,334		261,240	264,436
Segment Reporting Information, Operating Income (Loss) [Abstract]
Utility income taxes	-36,409		-36,190		-92,680	-95,992
Operating income	75,123		67,299		180,882	169,618
Segment Reporting Information, Profit (Loss) [Abstract]
Income before income taxes for reportable segments	108,727		103,334		261,240	264,436
Income taxes	-42,325		-40,794		-101,860	-104,324
Net Income	66,402		62,540		159,380	160,112
Regulated Operation
Segment Reporting Information [Abstract]
Revenues from external customers	424,924		462,247		1,032,196	1,119,980
Margin	225,621		211,523		495,691	473,035
Operations and maintenance expenses	71,424		70,193		137,574	130,832
Income from equity method investments	0		0		0	0
Operating income (loss) before income taxes	111,532		103,489		273,562	265,610
Income before income taxes for reportable segments	92,918		88,999		237,318	240,268
Segment Reporting Information, Profit (Loss) [Abstract]
Income before income taxes for reportable segments	92,918		88,999		237,318	240,268
Non Utility Regulated Activities
Segment Reporting Information [Abstract]
Revenues from external customers	0		0		0	0
Margin	0		0		0	0
Operations and maintenance expenses	20		8		51	14
Income from equity method investments	3,577		2,467		7,348	5,574
Operating income (loss) before income taxes	-20		-8		-51	-14
Income before income taxes for reportable segments	3,557		2,459		7,297	5,560
Segment Reporting Information, Operating Income (Loss) [Abstract]
Segment Operating Income Before Income Taxes	20		8		51	14
Segment Reporting Information, Profit (Loss) [Abstract]
Income before income taxes for reportable segments	3,557		2,459		7,297	5,560
Non Utility Unregulated Activities
Segment Reporting Information [Abstract]
Revenues from external customers	0		0		0	0
Margin	0		0		0	0
Operations and maintenance expenses	9		13		47	32
Income from equity method investments	12,265		11,893		16,759	18,728
Operating income (loss) before income taxes	-14		-17		-135	-119
Income before income taxes for reportable segments	12,252		11,876		16,625	18,608
Segment Reporting Information, Operating Income (Loss) [Abstract]
Segment Operating Income Before Income Taxes	14		17		135	119
Segment Reporting Information, Profit (Loss) [Abstract]
Income before income taxes for reportable segments	$12,252		$11,876		$16,625	$18,608
[1]	See Note 12 for amounts attributable to affiliates.