Employee Benefit Plans (Details) (USD $)	0 Months Ended	12 Months Ended
	Dec. 31, 2007	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Term Life Insurance Premiums Paid By Employer For Vp And Above		$ 27,000	$ 43,000	$ 56,000
Officers And Director Level Employees		28,000	25,000	24,000
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Noncurrent assets		28,258,000	0
Amounts Not Yet Recognized as a Component of Cost and Recognized in a Deferred Regulatory Account
Regulatory asset		(246,306,000)	(293,104,000)
Defined Contribution Plans Disclosure [Abstract]
Current Liability		199,000	160,000
Noncurrent Liability		3,328,000	2,412,000
Plan 401 K [Member]
Defined Contribution Plans Disclosure [Abstract]
Employer Contribution to Plan		5,688,000	5,400,000	5,203,000
Defined Contribution Plan, Maximum Annual Contribution Per Employee, Percent		5.00%
Description Of Defined Contribution Pension And Other Postretirement Plans		We maintain a 401(k) plan that is a profit-sharing plan under Section 401(a) of the Internal Revenue Code of 1986, as amended (the Tax Code), which includes qualified cash or deferred arrangements under Tax Code Section 401(k). The 401(k) plan is subject to the provisions of the Employee Retirement Income Security Act. Eligible employees who have completed 30 days of continuous service and have attained age 18 are eligible to participate. Participants may defer a portion of their base salary and cash incentive payments to the plan, and we match a portion of their contributions. Employee contributions vest immediately, and company contributions vest after six months of service. Employees receive a company match of 100% up to the first 5% of eligible pay contributed. Employees may contribute up to 50% of eligible pay to the 401(k) on a pre-tax basis, up to the Tax Code annual contribution and compensation limits. We automatically enroll all eligible non-participating employees in the 401(k) plan at a 2% contribution rate unless the employee chooses not to participate by notifying our record keeper. For employees who are automatically enrolled in the 401(k) plan, we automatically increase their contributions by 1% each year to a maximum of 5% unless the employee chooses to opt out of the automatic increase by contacting our record keeper. If the employee does not make an investment election, employee contributions and matches are automatically invested in a diversified portfolio of stocks and bonds. Participants may direct up to 20% of their contributions and company matching contributions as an investment in the Piedmont Stock Fund. Employees may change their contribution rate and investments at any time.
Standard Eligibility Age For Defined Contribution Plan		18 years
Service Required For Eligibility In Defined Contribution Plan		30 days
Employer Match Percentage		100.00%
Employee Contribution Cap		50.00%
Employee Contribution Rate At Enrollment		2.00%
Contribution Annual Automatic Deferral Increase		1.00%
Employee Contribution Automatic Increase Rate Cap		5.00%
Investment In Company Stock Cap		20.00%
Money Purchase Pension Plan [Member]
Defined Contribution Plans Disclosure [Abstract]
Employer Contribution to Plan		700,000
Employer Contribution Percentage		4.00%
Description Of Defined Contribution Pension And Other Postretirement Plans		Employees hired or rehired after December 31, 2007 cannot participate in the qualified pension plan but are participants in the Money Purchase Pension (MPP) plan, a defined contribution pension plan that allows the employee to direct the investments and assume the risk of investment returns. A defined contribution plan specifies the amount of the employer’s annual contribution to individual participant accounts established for the retirement benefit. Eligible employees who have completed 30 days of continuous service and have attained age 18 are eligible to participate. Under the MPP plan, we annually deposit a percentage of each participant’s pay into an account of the MPP plan. This contribution equals 4% of the participant’s compensation plus an additional 4% of compensation above the social security wage base up to the Internal Revenue Service (IRS) compensation limit. The participant is vested in this plan after three years of service.
Standard Eligibility Age For Defined Contribution Plan		18 years
Service Required For Eligibility In Defined Contribution Plan		30 days
Employer Contribution Percentage Above IRS Limit		4.00%
Plan Vesting Period Defined Contribution Plan		3 years
Defined Contribution Plans Estimated Future Employer Contributions In Next Fiscal Year		885,000
Defined Contribution Restoration Plan [Member]
Defined Contribution Plans Disclosure [Abstract]
Employer Contribution to Plan		434,000	422,000
Description Of Defined Contribution Pension And Other Postretirement Plans		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 informally funded annually through a rabbi trust with a bank as the trustee. We contribute 13% of the total cash compensation (base salary, short-term incentive and MVP incentive) that exceeds the IRS compensation limit to the DCR plan account of each covered executive. Participants may not contribute to the DCR plan. Vesting under the DCR plan is five-year cliff vesting, including service prior to adoption of the plan on January 1, 2009, of annual company contributions, and prospective five-year cliff vesting for the one-time opening balances of four Vice Presidents to compensate them for the loss of future benefits under this DCR plan as compared with a terminated SERP. Participants in the DCR plan may provide instructions to us for the deemed investment of their plan accounts. Distribution will occur upon separation of service or death of the participant.
Employer Contribution Percentage Above IRS Limit		13.00%
Plan Vesting Period Defined Contribution Plan		5 years
Vice Presidents Eligible For One Time Contribution New DCR Plan		4
Voluntary Deferral Plan [Member]
Defined Contribution Plans Disclosure [Abstract]
Employer Contribution to Plan		0
Deferral Limit As Percentage Of Base Salary		50.00%
Plan Deferral Limit As Percentage Of Annual Incentive Pay		95.00%
Distribution Deferral Time Period Minimum In Years		2 years
Private Equity Funds [Member]
Amounts Not Yet Recognized as a Component of Cost and Recognized in a Deferred Regulatory Account
Initial Unfunded Subscription Balance		12,000,000
Net Asset Value Unfunded Committments		7,400,000
Qualified Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plans General Information		We have a noncontributory, tax-qualified defined benefit pension plan (qualified pension plan) for our eligible employees. A defined benefit plan specifies the amount of benefit that an eligible participant eventually will receive upon retirement using information about that participant. An employee became eligible on the January 1 or July 1 following either the date on which he or she attained age 30 or attained age 21 and completed 1,000 hours of service during the 12-month period commencing on the employment date. Plan benefits are generally based on credited years of service and the level of compensation during the five consecutive years of the last ten years prior to retirement or termination during which the participant received the highest compensation. Our policy is to fund the plan in an amount not in excess of the amount that is deductible for income tax purposes. The qualified pension plan is closed to employees hired after December 31, 2007. Employees hired prior to January 1, 2008 continue to participate in the qualified pension plan. Employees are vested after five years of service and can be credited with up to a total of 35 years of service. When a vested employee leaves the company, his benefit payment will be calculated as the greater of the accrued benefit as of December 31, 2007 under a specific formula plus the accrued benefit calculated under a second formula for years of service after December 31, 2007, or the benefit for all years of service up to 35 years under the second formula.
Estimated Future Employee Contributions Next Fiscal Year		20,000,000
Reconciliation Of Changes In Plan Benefit Obligations And Fair Value Of Assets [Abstract]
Accumulated Benefit Obligation At Year End		230,175,000	245,361,000
Change In Benefit Obligation
Obligation at beginning of year		293,327,000	236,632,000
Service cost		12,005,000	9,573,000	8,508,000
Interest cost		9,946,000	10,640,000	11,024,000
Actuarial (gain) loss		(24,859,000)	54,852,000
Participant contributions		0	0
Administrative expenses		(534,000)	(420,000)
Benefit payments		(17,482,000)	(17,950,000)
Obligation at end of year		272,403,000	293,327,000	236,632,000
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at beginning of year		272,337,000	259,511,000
Actual return on plan assets		26,340,000	31,196,000
Employer contributions		20,000,000	0
Participant contributions		0	0
Administrative expenses		(534,000)	(420,000)
Benefit payments		(17,482,000)	(17,950,000)
Fair value at end of year		300,661,000	272,337,000	259,511,000
Funded status at year end - (under) over		28,258,000	(20,990,000)
Noncurrent assets		28,258,000	0
Current liabilities		0	0
Noncurrent liabilities		0	(20,990,000)
Net amount recognized		28,258,000	(20,990,000)
Amounts Not Yet Recognized as a Component of Cost and Recognized in a Deferred Regulatory Account
Unrecognized transition obligation		0	0
Unrecognized prior service (cost) credit		17,243,000	19,441,000
Unrecognized actuarial loss		(96,338,000)	(137,633,000)
Cumulative Employer Contribution In Excess Of Cost		107,353,000	97,202,000
Horizon For DBPP Long Term Rates Of Return		20 years
Benefit Obligation Weighted Average Assumptions [Abstract]
Discount Rate		4.55%	3.51%
Rate Of Compensation Increase		3.72%	3.76%
Net Periodic Benefits Cost Weighted Average Assumptions [Abstract]
Discount Rate		3.51%	4.67%	5.47%
Expected Long Term Rate Of Return On Plan Assets		8.00%	8.00%	8.00%
Rate Of Compensation Increase		3.76%	3.78%	3.87%
Defined Benefit Plan Estimated Future Benefit Payments Abstract
2014		25,918,000
2015		16,918,000
2016		15,169,000
2017		16,154,000
2018		18,672,000
2019 - 2023		106,226,000
Defined Benefit Plan Net Periodic Benefit Cost Abstract
Service cost		12,005,000	9,573,000	8,508,000
Interest cost		9,946,000	10,640,000	11,024,000
Expected return on plan assets		(21,105,000)	(20,289,000)	(20,608,000)
Amortization of transition obligation		0	0	0
Amortization of prior service cost (credit)		(2,198,000)	(2,198,000)	(2,198,000)
Amortization of net loss		11,202,000	5,966,000	3,547,000
Net periodic benefit (income) cost		9,850,000	3,692,000	273,000
Other Changes In Plan Assets And Benefit Obligatin Recognized Through Regulatory Asset Or Liability [Abstract]
Prior service cost		0	0	0
Net loss (gain)		(30,094,000)	43,945,000	17,539,000
Amounts Recognized As Component Of Net Periodic Benefit Cost [Abstract]
Amortization of transition obligation		0	0	0
Amortization of net loss		11,202,000	5,966,000	3,547,000
Amortization of prior service cost (credit)		(2,198,000)	(2,198,000)	(2,198,000)
Total recognized in regulatory asset (liability)		(39,098,000)	40,177,000	16,190,000
Total Recognized In Net Periodic Benefit Cost And Regulatory Asset (Liability)		(29,248,000)	43,869,000	16,463,000
Estimated Amortization And Expected Refunds [Abstract]
Amortization of unrecognized prior service cost (credit)		(2,198,000)
Amortization of unrecognized actuarial loss		7,138,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		100.00%	100.00%
Defined Benefit Plan Fair Value Of Plan Assets		300,661,000	272,337,000	259,511,000
Reconciliation Of Plan Assets Classified As Level 3 Roll Forward
Fair value at beginning of year		272,337,000	259,511,000
Actual return on plan assets:
Fair value at end of year		300,661,000	272,337,000	259,511,000
Standard Eligibility Age For Defined Benefit Plan		30 years
Duration To Complete Service Requirement		12 months
Maximum Credited Service Period		35 years
Period Of Compensation For Benefit Calculation		10 years
Years Of Highest Compensation For Benefit Calculation		5 years
Plan Vesting Period Defined Benefit Plan		5 years
Qualified Pension [Member] | Amounts Not Yet Recognized As Component Of Pension Liability [Member]
Amounts Not Yet Recognized as a Component of Cost and Recognized in a Deferred Regulatory Account
Regulatory asset		(79,095,000)	(118,192,000)
Qualified Pension [Member] | Minimum [Member]
Actual return on plan assets:
Standard Eligibility Age For Defined Benefit Plan		21 years
Qualified Pension [Member] | Cash [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		5,722,000	5,346,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		2.00%	2.00%
Defined Benefit Plan Fair Value Of Plan Assets		5,722,000	5,346,000
Actual return on plan assets:
Fair value at end of year		5,722,000	5,346,000
Qualified Pension [Member] | Total Fixed Income Securities [Member]
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		38.00%	45.00%
Target Plan Asset Allocations		45.00%
Qualified Pension [Member] | US Treasuries [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		24,078,000	17,544,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		8.00%	6.00%
Defined Benefit Plan Fair Value Of Plan Assets		24,078,000	17,544,000
Actual return on plan assets:
Fair value at end of year		24,078,000	17,544,000
Qualified Pension [Member] | Long Duration Bonds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		34,041,000	63,565,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		11.00%	23.00%
Defined Benefit Plan Fair Value Of Plan Assets		34,041,000	63,565,000
Actual return on plan assets:
Fair value at end of year		34,041,000	63,565,000
Qualified Pension [Member] | Corporate Bonds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		42,701,000	26,368,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		14.00%	10.00%
Defined Benefit Plan Fair Value Of Plan Assets		42,701,000	26,368,000
Actual return on plan assets:
Fair value at end of year		42,701,000	26,368,000
Qualified Pension [Member] | High Yield Bonds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		14,680,000	13,777,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		5.00%	5.00%
Defined Benefit Plan Fair Value Of Plan Assets		14,680,000	13,777,000
Actual return on plan assets:
Fair value at end of year		14,680,000	13,777,000
Qualified Pension [Member] | Collateralized Mortgage Backed Securities [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		1,098,000	1,513,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		0.00%	1.00%
Defined Benefit Plan Fair Value Of Plan Assets		1,098,000	1,513,000
Actual return on plan assets:
Fair value at end of year		1,098,000	1,513,000
Qualified Pension [Member] | Municipals [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	345,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		0.00%	0.00%
Defined Benefit Plan Fair Value Of Plan Assets		0	345,000
Actual return on plan assets:
Fair value at end of year		0	345,000
Qualified Pension [Member] | Derivatives [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		(11,000)	(89,000)
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		0.00%	0.00%
Defined Benefit Plan Fair Value Of Plan Assets		(11,000)	(89,000)
Actual return on plan assets:
Fair value at end of year		(11,000)	(89,000)
Qualified Pension [Member] | Derivatives [Member] | Maximum [Member]
Plan Assets Fair Value Hierarchy [Abstract]
Investment Limititation Percentage		10.00%
Qualified Pension [Member] | Total Equity Securities
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		43.00%	36.00%
Target Plan Asset Allocations		35.00%
Qualified Pension [Member] | Large Cap Core Index [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		12,023,000	10,260,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		4.00%	4.00%
Defined Benefit Plan Fair Value Of Plan Assets		12,023,000	10,260,000
Actual return on plan assets:
Fair value at end of year		12,023,000	10,260,000
Qualified Pension [Member] | Large Cap Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		16,908,000	10,427,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		6.00%	4.00%
Defined Benefit Plan Fair Value Of Plan Assets		16,908,000	10,427,000
Actual return on plan assets:
Fair value at end of year		16,908,000	10,427,000
Qualified Pension [Member] | Large Cap Growth [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		17,823,000	15,252,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		6.00%	6.00%
Defined Benefit Plan Fair Value Of Plan Assets		17,823,000	15,252,000
Actual return on plan assets:
Fair value at end of year		17,823,000	15,252,000
Qualified Pension [Member] | Small Cap Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		30,831,000	26,335,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		10.00%	10.00%
Defined Benefit Plan Fair Value Of Plan Assets		30,831,000	26,335,000
Actual return on plan assets:
Fair value at end of year		30,831,000	26,335,000
Qualified Pension [Member] | Common Trust Fund International Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		24,460,000
Amounts Not Yet Recognized as a Component of Cost and Recognized in a Deferred Regulatory Account
Net Asset Value Redemption Notice Period		5 days
Net Asset Value Redemption Frequency		Daily
Net Asset Value Redemption Restriction Description		None
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		8.00%
Defined Benefit Plan Fair Value Of Plan Assets		24,460,000
Actual return on plan assets:
Fair value at end of year		24,460,000
Qualified Pension [Member] | International Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year			14,376,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations			5.00%
Defined Benefit Plan Fair Value Of Plan Assets			14,376,000
Actual return on plan assets:
Fair value at end of year			14,376,000
Qualified Pension [Member] | Common Trust Fund International Growth [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at beginning of year		18,678,000
Fair value at end of year		27,270,000
Amounts Not Yet Recognized as a Component of Cost and Recognized in a Deferred Regulatory Account
Net Asset Value Redemption Notice Period		30 days
Net Asset Value Redemption Frequency		Monthly
Net Asset Value Redemption Restriction Description		None
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		9.00%	7.00%
Defined Benefit Plan Fair Value Of Plan Assets		27,270,000
Reconciliation Of Plan Assets Classified As Level 3 Roll Forward
Fair value at beginning of year		18,678,000
Actual return on plan assets:
Fair value at end of year		27,270,000
Qualified Pension [Member] | Total Real Estate [Member]
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		5.00%	6.00%
Target Plan Asset Allocations		5.00%
Qualified Pension [Member] | Global Reit [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		15,042,000	16,252,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		5.00%	6.00%
Defined Benefit Plan Fair Value Of Plan Assets		15,042,000	16,252,000
Actual return on plan assets:
Fair value at end of year		15,042,000	16,252,000
Qualified Pension [Member] | Total Other Investments [Member]
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		12.00%	11.00%
Target Plan Asset Allocations		15.00%
Qualified Pension [Member] | Hedge Funds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at beginning of year		16,995,000
Fair value at end of year		18,571,000
Amounts Not Yet Recognized as a Component of Cost and Recognized in a Deferred Regulatory Account
Net Asset Value Redemption Notice Period		65 days
Net Asset Value Redemption Frequency		Quarterly
Net Asset Value Redemption Restriction Description		Redeemed in whole or part but not less than the minimum redemption amount for each currency. Redemption within one year of purchase is subject to 1.5% redemption fee. Redeemed on "first in first out" basis. None of our investment is subject to the redemption fee. Fund's Board of Directors may limit or suspend share redemptions until a further notification ending suspension. No such notification has been received as of October 31, 2013.
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		6.00%	6.00%
Defined Benefit Plan Fair Value Of Plan Assets		18,571,000
Reconciliation Of Plan Assets Classified As Level 3 Roll Forward
Fair value at beginning of year		16,995,000
Actual return on plan assets:
Fair value at end of year		18,571,000
Qualified Pension [Member] | Private Equity Funds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at beginning of year		3,522,000
Fair value at end of year		4,659,000
Amounts Not Yet Recognized as a Component of Cost and Recognized in a Deferred Regulatory Account
Net Asset Value Redemption Frequency		Limited
Net Asset Value Redemption Restriction Description		Investors have only very limited withdrawal rights for specific legal or regulatory reasons. Any transfer of interest will be subject to approval.
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		2.00%	1.00%
Target Plan Asset Allocations		5.00%
Defined Benefit Plan Fair Value Of Plan Assets		4,659,000
Reconciliation Of Plan Assets Classified As Level 3 Roll Forward
Fair value at beginning of year		3,522,000
Actual return on plan assets:
Fair value at end of year		4,659,000
Qualified Pension [Member] | Private Equity Funds [Member] | Maximum [Member]
Amounts Not Yet Recognized as a Component of Cost and Recognized in a Deferred Regulatory Account
Net Asset Value Liquidating Investment Remaining Period		12 years
Qualified Pension [Member] | Private Equity Funds [Member] | Minimum [Member]
Amounts Not Yet Recognized as a Component of Cost and Recognized in a Deferred Regulatory Account
Net Asset Value Liquidating Investment Remaining Period		10 years
Qualified Pension [Member] | Commodities [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at beginning of year		11,871,000
Fair value at end of year		10,765,000
Amounts Not Yet Recognized as a Component of Cost and Recognized in a Deferred Regulatory Account
Net Asset Value Redemption Notice Period		35 days
Net Asset Value Redemption Frequency		Monthly
Net Asset Value Redemption Restriction Description		Redemption within one year of purchase is subject to 1% redemption fee. None of our investment is subject to the redemption fee. If 95% or more of the balance is requested, 95% of the balance will be paid within 30 days. Any outstanding balance or interest owed will be paid after the annual audit is complete.
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		4.00%	4.00%
Defined Benefit Plan Fair Value Of Plan Assets		10,765,000
Reconciliation Of Plan Assets Classified As Level 3 Roll Forward
Fair value at beginning of year		11,871,000
Actual return on plan assets:
Fair value at end of year		10,765,000
Qualified Pension [Member] | Total Investments [Member]
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		100.00%	100.00%
Qualified Pension [Member] | Quoted Prices In Active Markets [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		112,879,000	112,022,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		37.00%	41.00%
Defined Benefit Plan Fair Value Of Plan Assets		112,879,000	112,022,000
Actual return on plan assets:
Fair value at end of year		112,879,000	112,022,000
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | Cash [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		5,566,000	5,346,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		5,566,000	5,346,000
Actual return on plan assets:
Fair value at end of year		5,566,000	5,346,000
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | US Treasuries [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | Long Duration Bonds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | Corporate Bonds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | High Yield Bonds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		14,680,000	13,777,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		14,680,000	13,777,000
Actual return on plan assets:
Fair value at end of year		14,680,000	13,777,000
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | Collateralized Mortgage Backed Securities [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | Municipals [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | Derivatives [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		6,000	(3,000)
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		6,000	(3,000)
Actual return on plan assets:
Fair value at end of year		6,000	(3,000)
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | Large Cap Core Index [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		12,023,000	10,260,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		12,023,000	10,260,000
Actual return on plan assets:
Fair value at end of year		12,023,000	10,260,000
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | Large Cap Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		16,908,000	10,427,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		16,908,000	10,427,000
Actual return on plan assets:
Fair value at end of year		16,908,000	10,427,000
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | Large Cap Growth [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		17,823,000	15,252,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		17,823,000	15,252,000
Actual return on plan assets:
Fair value at end of year		17,823,000	15,252,000
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | Small Cap Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		30,831,000	26,335,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		30,831,000	26,335,000
Actual return on plan assets:
Fair value at end of year		30,831,000	26,335,000
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | Common Trust Fund International Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0
Actual return on plan assets:
Fair value at end of year		0
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | International Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year			14,376,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets			14,376,000
Actual return on plan assets:
Fair value at end of year			14,376,000
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | Common Trust Fund International Growth [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | Global Reit [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		15,042,000	16,252,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		15,042,000	16,252,000
Actual return on plan assets:
Fair value at end of year		15,042,000	16,252,000
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | Hedge Funds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | Private Equity Funds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Quoted Prices In Active Markets [Member] | Commodities [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Other Observable Inputs [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		183,123,000	156,793,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		61.00%	58.00%
Defined Benefit Plan Fair Value Of Plan Assets		183,123,000	156,793,000
Actual return on plan assets:
Fair value at end of year		183,123,000	156,793,000
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | Cash [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		156,000	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		156,000	0
Actual return on plan assets:
Fair value at end of year		156,000	0
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | US Treasuries [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		24,078,000	17,544,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		24,078,000	17,544,000
Actual return on plan assets:
Fair value at end of year		24,078,000	17,544,000
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | Long Duration Bonds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		34,041,000	63,565,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		34,041,000	63,565,000
Actual return on plan assets:
Fair value at end of year		34,041,000	63,565,000
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | Corporate Bonds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		42,701,000	26,368,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		42,701,000	26,368,000
Actual return on plan assets:
Fair value at end of year		42,701,000	26,368,000
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | High Yield Bonds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | Collateralized Mortgage Backed Securities [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		1,098,000	1,513,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		1,098,000	1,513,000
Actual return on plan assets:
Fair value at end of year		1,098,000	1,513,000
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | Municipals [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	345,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	345,000
Actual return on plan assets:
Fair value at end of year		0	345,000
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | Derivatives [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		(17,000)	(86,000)
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		(17,000)	(86,000)
Actual return on plan assets:
Fair value at end of year		(17,000)	(86,000)
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | Large Cap Core Index [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | Large Cap Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | Large Cap Growth [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | Small Cap Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | Common Trust Fund International Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		24,460,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		24,460,000
Actual return on plan assets:
Fair value at end of year		24,460,000
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | International Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year			0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets			0
Actual return on plan assets:
Fair value at end of year			0
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | Common Trust Fund International Growth [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		27,270,000	18,678,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		27,270,000	18,678,000
Actual return on plan assets:
Fair value at end of year		27,270,000	18,678,000
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | Global Reit [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | Hedge Funds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		18,571,000	16,995,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		18,571,000	16,995,000
Actual return on plan assets:
Fair value at end of year		18,571,000	16,995,000
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | Private Equity Funds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Other Observable Inputs [Member] | Commodities [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		10,765,000	11,871,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		10,765,000	11,871,000
Actual return on plan assets:
Fair value at end of year		10,765,000	11,871,000
Qualified Pension [Member] | Significant Unobservable Inputs [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at beginning of year		3,522,000	16,604,000
Fair value at end of year		4,659,000	3,522,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		2.00%	1.00%
Defined Benefit Plan Fair Value Of Plan Assets		4,659,000	3,522,000
Reconciliation Of Plan Assets Classified As Level 3 Roll Forward
Fair value at beginning of year		3,522,000	16,604,000
Actual return on plan assets:
Relating to assets still held at the reporting date		116,000	13,000
Relating to assets sold during the period		61,000	145,000
Purchases, sales and settlements (net)		960,000	1,439,000
Transfer in/out of Level 3		0	(14,679,000)
Fair value at end of year		4,659,000	3,522,000
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | Cash [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | US Treasuries [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | Long Duration Bonds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | Corporate Bonds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | High Yield Bonds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | Collateralized Mortgage Backed Securities [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | Municipals [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | Derivatives [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | Large Cap Core Index [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | Large Cap Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | Large Cap Growth [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | Small Cap Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | Common Trust Fund International Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0
Actual return on plan assets:
Fair value at end of year		0
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | International Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year			0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets			0
Actual return on plan assets:
Fair value at end of year			0
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | Common Trust Fund International Growth [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | Global Reit [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | Hedge Funds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at beginning of year		0	6,207,000
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Reconciliation Of Plan Assets Classified As Level 3 Roll Forward
Fair value at beginning of year		0	6,207,000
Actual return on plan assets:
Relating to assets still held at the reporting date		0	0
Relating to assets sold during the period		0	0
Purchases, sales and settlements (net)		0	0
Transfer in/out of Level 3		0	(6,207,000)
Fair value at end of year		0	0
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | Private Equity Funds [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at beginning of year		3,522,000	1,925,000
Fair value at end of year		4,659,000	3,522,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		4,659,000	3,522,000
Reconciliation Of Plan Assets Classified As Level 3 Roll Forward
Fair value at beginning of year		3,522,000	1,925,000
Actual return on plan assets:
Relating to assets still held at the reporting date		116,000	13,000
Relating to assets sold during the period		61,000	145,000
Purchases, sales and settlements (net)		960,000	1,439,000
Transfer in/out of Level 3		0	0
Fair value at end of year		4,659,000	3,522,000
Qualified Pension [Member] | Significant Unobservable Inputs [Member] | Commodities [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at beginning of year		0	8,472,000
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Reconciliation Of Plan Assets Classified As Level 3 Roll Forward
Fair value at beginning of year		0	8,472,000
Actual return on plan assets:
Relating to assets still held at the reporting date		0	0
Relating to assets sold during the period		0	0
Purchases, sales and settlements (net)		0	0
Transfer in/out of Level 3		0	(8,472,000)
Fair value at end of year		0	0
Non Qualified Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated Future Employee Contributions Next Fiscal Year		444,000
Reconciliation Of Changes In Plan Benefit Obligations And Fair Value Of Assets [Abstract]
Accumulated Benefit Obligation At Year End		4,736,000	5,569,000
Change In Benefit Obligation
Obligation at beginning of year		5,569,000	5,219,000
Service cost		0	39,000	45,000
Interest cost		157,000	203,000	209,000
Actuarial (gain) loss		(540,000)	629,000
Participant contributions		0	0
Administrative expenses		0	0
Benefit payments		(450,000)	(521,000)
Obligation at end of year		4,736,000	5,569,000	5,219,000
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at beginning of year		0	0
Actual return on plan assets		0	0
Employer contributions		450,000	521,000
Participant contributions		0	0
Administrative expenses		0	0
Benefit payments		(450,000)	(521,000)
Fair value at end of year		0	0	0
Funded status at year end - (under) over		(4,736,000)	(5,569,000)
Noncurrent assets		0	0
Current liabilities		(445,000)	(502,000)
Noncurrent liabilities		(4,291,000)	(5,067,000)
Net amount recognized		(4,736,000)	(5,569,000)
Amounts Not Yet Recognized as a Component of Cost and Recognized in a Deferred Regulatory Account
Unrecognized transition obligation		0	0
Unrecognized prior service (cost) credit		(196,000)	(277,000)
Unrecognized actuarial loss		(820,000)	(1,521,000)
Cumulative Employer Contribution In Excess Of Cost		(3,720,000)	(3,771,000)
Benefit Obligation Weighted Average Assumptions [Abstract]
Discount Rate		3.98%	2.95%
Net Periodic Benefits Cost Weighted Average Assumptions [Abstract]
Discount Rate		2.95%	4.10%	4.37%
Defined Benefit Plan Estimated Future Benefit Payments Abstract
2014		444,000
2015		458,000
2016		434,000
2017		410,000
2018		383,000
2019 - 2023		1,890,000
Defined Benefit Plan Net Periodic Benefit Cost Abstract
Service cost		0	39,000	45,000
Interest cost		157,000	203,000	209,000
Expected return on plan assets		0	0	0
Amortization of transition obligation		0	0	0
Amortization of prior service cost (credit)		81,000	81,000	20,000
Amortization of net loss		161,000	49,000	41,000
Net periodic benefit (income) cost		399,000	372,000	315,000
Other Changes In Plan Assets And Benefit Obligatin Recognized Through Regulatory Asset Or Liability [Abstract]
Prior service cost		0	0	290,000
Net loss (gain)		(540,000)	629,000	130,000
Amounts Recognized As Component Of Net Periodic Benefit Cost [Abstract]
Amortization of transition obligation		0	0	0
Amortization of net loss		161,000	49,000	41,000
Amortization of prior service cost (credit)		81,000	81,000	20,000
Total recognized in regulatory asset (liability)		(782,000)	499,000	359,000
Total Recognized In Net Periodic Benefit Cost And Regulatory Asset (Liability)		(383,000)	871,000	674,000
Estimated Amortization And Expected Refunds [Abstract]
Amortization of unrecognized prior service cost (credit)		81,000
Amortization of unrecognized actuarial loss		47,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0	0
Reconciliation Of Plan Assets Classified As Level 3 Roll Forward
Fair value at beginning of year		0	0
Actual return on plan assets:
Fair value at end of year		0	0	0
Non Qualified Pension [Member] | Amounts Not Yet Recognized As Component Of Pension Liability [Member]
Amounts Not Yet Recognized as a Component of Cost and Recognized in a Deferred Regulatory Account
Regulatory asset		(1,016,000)	(1,798,000)
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plans General Information		We provide certain postretirement health care and life insurance benefits to eligible retirees. The liability associated with such benefits is funded in irrevocable trust funds that can only be used to pay the benefits. Employees are first eligible to retire and receive these benefits at age 55 with ten or more years of service after the age of 45. Employees who met this requirement in 1993 or who retired prior to 1993 are in a “grandfathered” group for whom we pay the full cost of the retiree’s coverage. Retirees not in the grandfathered group have a portion of the cost of retiree coverage paid by us, subject to certain annual contribution limits. Retirees are responsible for the full cost of dependent coverage. Effective January 1, 2008, new employees have to complete ten years of service after age 50 to be eligible for benefits, and no benefits are provided to those employees after age 65 when they are automatically eligible for Medicare benefits to cover health costs. Our OPEB plan includes a defined dollar benefit to pay the premiums for Medicare Part D. Employees who meet the eligibility requirements to retire also receive a life insurance benefit. For employees who retire after July 1, 2005, this benefit is $15,000. The life insurance amount for employees who retired prior to this date was calculated as a percentage of their basic life insurance prior to retirement.
Estimated Future Employee Contributions Next Fiscal Year		1,500,000
Change In Benefit Obligation
Obligation at beginning of year		34,830,000	31,900,000
Service cost		1,327,000	1,387,000	1,398,000
Interest cost		1,130,000	1,347,000	1,495,000
Actuarial (gain) loss		(1,094,000)	2,630,000
Participant contributions		641,000	788,000
Administrative expenses		0	0
Benefit payments		(3,156,000)	(3,222,000)
Obligation at end of year		33,678,000	34,830,000	31,900,000
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at beginning of year		23,663,000	22,045,000
Actual return on plan assets		2,848,000	1,972,000
Employer contributions		1,965,000	2,080,000
Participant contributions		641,000	788,000
Administrative expenses		0	0
Benefit payments		(3,156,000)	(3,222,000)
Fair value at end of year		25,961,000	23,663,000	22,045,000
Funded status at year end - (under) over		(7,717,000)	(11,167,000)
Noncurrent assets		0	0
Current liabilities		0	0
Noncurrent liabilities		(7,717,000)	(11,167,000)
Net amount recognized		(7,717,000)	(11,167,000)
Amounts Not Yet Recognized as a Component of Cost and Recognized in a Deferred Regulatory Account
Unrecognized transition obligation		0	(667,000)
Unrecognized prior service (cost) credit		0	0
Unrecognized actuarial loss		(354,000)	(2,633,000)
Cumulative Employer Contribution In Excess Of Cost		(7,363,000)	(7,867,000)
Benefit Obligation Weighted Average Assumptions [Abstract]
Discount Rate		4.44%	3.34%
Net Periodic Benefits Cost Weighted Average Assumptions [Abstract]
Discount Rate		3.34%	4.36%	4.85%
Expected Long Term Rate Of Return On Plan Assets		8.00%	8.00%	8.00%
Defined Benefit Plan Estimated Future Benefit Payments Abstract
2014		2,140,000
2015		2,262,000
2016		2,322,000
2017		2,417,000
2018		2,507,000
2019 - 2023		13,640,000
Assumed Health Care Cost Rate Trends Abstract
Health Care Cost Trend Rate Assumed For Next Fiscal Year		7.40%	7.50%
Ultimate Health Care Cost Trend Rate		5.00%	5.00%
Year That Rate Reaches Ultimate Trend Rate		2027	2027
Effect Of Health Care Cost Trend Rate Assumptions [Abstract]
Effect of One Percentage Point Increase on Service and Interest Cost Components		21,000
Effect of One Percentage Point Decrease on Service and Interest Cost Components		27,000
Effect Of One Percentage Point Increase on Postretirement Benefit Obligation		690,000
Effect of One Percentage Point Decrease on Postretirement Benefit Obligation		699,000
Defined Benefit Plan Net Periodic Benefit Cost Abstract
Service cost		1,327,000	1,387,000	1,398,000
Interest cost		1,130,000	1,347,000	1,495,000
Expected return on plan assets		(1,663,000)	(1,551,000)	(1,534,000)
Amortization of transition obligation		667,000	667,000	667,000
Amortization of prior service cost (credit)		0	0	0
Amortization of net loss		0	0	0
Net periodic benefit (income) cost		1,461,000	1,850,000	2,026,000
Other Changes In Plan Assets And Benefit Obligatin Recognized Through Regulatory Asset Or Liability [Abstract]
Prior service cost		0	0	0
Net loss (gain)		(2,278,000)	2,209,000	415,000
Amounts Recognized As Component Of Net Periodic Benefit Cost [Abstract]
Amortization of transition obligation		667,000	667,000	667,000
Amortization of net loss		0	0	0
Amortization of prior service cost (credit)		0	0	0
Total recognized in regulatory asset (liability)		(2,945,000)	1,542,000	(252,000)
Total Recognized In Net Periodic Benefit Cost And Regulatory Asset (Liability)		(1,484,000)	3,392,000	1,774,000
Estimated Amortization And Expected Refunds [Abstract]
Amortization of unrecognized prior service cost (credit)		0
Amortization of unrecognized actuarial loss		0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		100.00%	100.00%
Defined Benefit Plan Fair Value Of Plan Assets		25,961,000	23,663,000	22,045,000
Reconciliation Of Plan Assets Classified As Level 3 Roll Forward
Fair value at beginning of year		23,663,000	22,045,000
Actual return on plan assets:
Fair value at end of year		25,961,000	23,663,000	22,045,000
Standard Eligibility Age For Defined Benefit Plan	45 years	50 years
Service Required For Eligibility In Defined Benefit Plan	10 years	10 years
Plan Vesting Period Defined Benefit Plan		65 years
Benefits Provided After Employee Is Eligible for Medicare Benefits		0
Term Life Insurance Per Individual Benefit Provided By Employer		15,000
Other Benefits [Member] | Amounts Not Yet Recognized As Component Of Pension Liability [Member]
Amounts Not Yet Recognized as a Component of Cost and Recognized in a Deferred Regulatory Account
Regulatory asset		(354,000)	(3,300,000)
Other Benefits [Member] | Cash [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at beginning of year		926,000
Fair value at end of year		982,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		4.00%	4.00%
Target Plan Asset Allocations		3.00%
Defined Benefit Plan Fair Value Of Plan Assets		982,000
Reconciliation Of Plan Assets Classified As Level 3 Roll Forward
Fair value at beginning of year		926,000
Actual return on plan assets:
Fair value at end of year		982,000
Other Benefits [Member] | Total Fixed Income Securities [Member]
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		46.00%	46.00%
Target Plan Asset Allocations		45.00%
Other Benefits [Member] | US Treasuries [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		2,582,000	2,345,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		10.00%	10.00%
Defined Benefit Plan Fair Value Of Plan Assets		2,582,000	2,345,000
Actual return on plan assets:
Fair value at end of year		2,582,000	2,345,000
Other Benefits [Member] | Corporate Bonds [Member]
Amounts Not Yet Recognized as a Component of Cost and Recognized in a Deferred Regulatory Account
Investment Maturity Date		within 10 years
Other Benefits [Member] | Corporate Bonds Other Fixed Income Securities [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		9,232,000	8,474,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		36.00%	36.00%
Defined Benefit Plan Fair Value Of Plan Assets		9,232,000	8,474,000
Actual return on plan assets:
Fair value at end of year		9,232,000	8,474,000
Other Benefits [Member] | High Yield Bonds [Member]
Plan Assets Fair Value Hierarchy [Abstract]
Target Plan Asset Allocations		5.00%
Other Benefits [Member] | Total Equity Securities
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		45.00%	45.00%
Target Plan Asset Allocations		47.00%
Other Benefits [Member] | Large Cap Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		1,327,000	1,221,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		5.00%	5.00%
Defined Benefit Plan Fair Value Of Plan Assets		1,327,000	1,221,000
Actual return on plan assets:
Fair value at end of year		1,327,000	1,221,000
Other Benefits [Member] | Large Cap Growth [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		1,352,000	1,149,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		5.00%	5.00%
Defined Benefit Plan Fair Value Of Plan Assets		1,352,000	1,149,000
Actual return on plan assets:
Fair value at end of year		1,352,000	1,149,000
Other Benefits [Member] | Small Cap Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		1,331,000	1,177,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		5.00%	5.00%
Defined Benefit Plan Fair Value Of Plan Assets		1,331,000	1,177,000
Actual return on plan assets:
Fair value at end of year		1,331,000	1,177,000
Other Benefits [Member] | Small Cap Growth [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		1,313,000	1,155,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		5.00%	5.00%
Defined Benefit Plan Fair Value Of Plan Assets		1,313,000	1,155,000
Actual return on plan assets:
Fair value at end of year		1,313,000	1,155,000
Other Benefits [Member] | Large Cap Index [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		2,384,000	2,148,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		9.00%	9.00%
Defined Benefit Plan Fair Value Of Plan Assets		2,384,000	2,148,000
Actual return on plan assets:
Fair value at end of year		2,384,000	2,148,000
Other Benefits [Member] | International Blend [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		4,206,000	3,907,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		16.00%	16.00%
Defined Benefit Plan Fair Value Of Plan Assets		4,206,000	3,907,000
Actual return on plan assets:
Fair value at end of year		4,206,000	3,907,000
Other Benefits [Member] | Total Real Estate [Member]
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		5.00%	5.00%
Other Benefits [Member] | Global Reit [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at beginning of year		1,161,000
Fair value at end of year		1,252,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		5.00%	5.00%
Target Plan Asset Allocations		5.00%
Defined Benefit Plan Fair Value Of Plan Assets		1,252,000
Reconciliation Of Plan Assets Classified As Level 3 Roll Forward
Fair value at beginning of year		1,161,000
Actual return on plan assets:
Fair value at end of year		1,252,000
Other Benefits [Member] | Total Investments [Member]
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		100.00%	100.00%
Other Benefits [Member] | Quoted Prices In Active Markets [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		25,961,000	23,663,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		100.00%	100.00%
Defined Benefit Plan Fair Value Of Plan Assets		25,961,000	23,663,000
Actual return on plan assets:
Fair value at end of year		25,961,000	23,663,000
Other Benefits [Member] | Quoted Prices In Active Markets [Member] | Cash [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		982,000	926,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		982,000	926,000
Actual return on plan assets:
Fair value at end of year		982,000	926,000
Other Benefits [Member] | Quoted Prices In Active Markets [Member] | US Treasuries [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		2,582,000	2,345,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		2,582,000	2,345,000
Actual return on plan assets:
Fair value at end of year		2,582,000	2,345,000
Other Benefits [Member] | Quoted Prices In Active Markets [Member] | Corporate Bonds Other Fixed Income Securities [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		9,232,000	8,474,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		9,232,000	8,474,000
Actual return on plan assets:
Fair value at end of year		9,232,000	8,474,000
Other Benefits [Member] | Quoted Prices In Active Markets [Member] | Large Cap Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		1,327,000	1,221,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		1,327,000	1,221,000
Actual return on plan assets:
Fair value at end of year		1,327,000	1,221,000
Other Benefits [Member] | Quoted Prices In Active Markets [Member] | Large Cap Growth [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		1,352,000	1,149,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		1,352,000	1,149,000
Actual return on plan assets:
Fair value at end of year		1,352,000	1,149,000
Other Benefits [Member] | Quoted Prices In Active Markets [Member] | Small Cap Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		1,331,000	1,177,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		1,331,000	1,177,000
Actual return on plan assets:
Fair value at end of year		1,331,000	1,177,000
Other Benefits [Member] | Quoted Prices In Active Markets [Member] | Small Cap Growth [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		1,313,000	1,155,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		1,313,000	1,155,000
Actual return on plan assets:
Fair value at end of year		1,313,000	1,155,000
Other Benefits [Member] | Quoted Prices In Active Markets [Member] | Large Cap Index [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		2,384,000	2,148,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		2,384,000	2,148,000
Actual return on plan assets:
Fair value at end of year		2,384,000	2,148,000
Other Benefits [Member] | Quoted Prices In Active Markets [Member] | International Blend [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		4,206,000	3,907,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		4,206,000	3,907,000
Actual return on plan assets:
Fair value at end of year		4,206,000	3,907,000
Other Benefits [Member] | Quoted Prices In Active Markets [Member] | Global Reit [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		1,252,000	1,161,000
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		1,252,000	1,161,000
Actual return on plan assets:
Fair value at end of year		1,252,000	1,161,000
Other Benefits [Member] | Significant Other Observable Inputs [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		0.00%	0.00%
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Other Observable Inputs [Member] | Cash [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Other Observable Inputs [Member] | US Treasuries [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Other Observable Inputs [Member] | Corporate Bonds Other Fixed Income Securities [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Other Observable Inputs [Member] | Large Cap Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Other Observable Inputs [Member] | Large Cap Growth [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Other Observable Inputs [Member] | Small Cap Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Other Observable Inputs [Member] | Small Cap Growth [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Other Observable Inputs [Member] | Large Cap Index [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Other Observable Inputs [Member] | International Blend [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Other Observable Inputs [Member] | Global Reit [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Unobservable Inputs [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Weighted Average Asset Allocations		0.00%	0.00%
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Unobservable Inputs [Member] | Cash [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Unobservable Inputs [Member] | US Treasuries [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Unobservable Inputs [Member] | Corporate Bonds Other Fixed Income Securities [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Unobservable Inputs [Member] | Large Cap Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Unobservable Inputs [Member] | Large Cap Growth [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Unobservable Inputs [Member] | Small Cap Value [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Unobservable Inputs [Member] | Small Cap Growth [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Unobservable Inputs [Member] | Large Cap Index [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Unobservable Inputs [Member] | International Blend [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
Other Benefits [Member] | Significant Unobservable Inputs [Member] | Global Reit [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward
Fair value at end of year		0	0
Plan Assets Fair Value Hierarchy [Abstract]
Defined Benefit Plan Fair Value Of Plan Assets		0	0
Actual return on plan assets:
Fair value at end of year		0	0
NCNG SERP [Member]
Net Periodic Benefits Cost Weighted Average Assumptions [Abstract]
Discount Rate		3.89%
Directors SERP [Member]
Net Periodic Benefits Cost Weighted Average Assumptions [Abstract]
Discount Rate		4.09%
Piedmont SERP [Member]
Net Periodic Benefits Cost Weighted Average Assumptions [Abstract]
Discount Rate		3.31%
Pension [Member]
Amounts Not Yet Recognized as a Component of Cost and Recognized in a Deferred Regulatory Account
Defined Benefit Plan Measurement Date		31-Oct
Defined Benefit Plan Actuarial Gains And Losses Amortization Corridor		5 years
Gains And Losses Amortized In Excess Of Percentage		10.00%
Defined Benefit Pension Plan Funding Target		100.00%
Supplemental Executive Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plans General Information		We have pension liabilities related to supplemental executive retirement plans (SERPs) for certain former employees, non-employee directors or surviving spouses. There are no assets related to these SERPs, and no additional benefits accrue to the participants. Payments to the participants are made from operating funds during the year.
Actual return on plan assets:
Assets for Participant Benefits		0
Officers and Director-Level Employees Life Insurance [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plans General Information		We also provide a term life insurance benefit equal to $200,000 to all officers and director-level employees for which we bear the cost of the policies.
Actual return on plan assets:
Term Life Insurance Per Individual Benefit Provided By Employer		$ 200,000
Certain Officers Vice President And Above Life Insurance [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plans General Information		We provide term life insurance policies for certain officers at the vice president level and above who were former participants in a terminated SERP; the level of the insurance benefit is dependent upon the level of the benefit provided under the terminated SERP. These life insurance policies are owned exclusively by each officer. Premiums on these policies are paid and expensed.