Fair Value of Financial Instruments (Details-3)	9 Months Ended	12 Months Ended
Sep. 30, 2014	Dec. 31, 2013
Fair Value Inputs Assets Quantitative Information [Line Items]
Basis adjustment - on peak	97.50%	94.20%
Basis adjustment - off peak	94.40%	92.60%
US Treasury Bill Securities [Member]
Deferred compensation plan [Abstract]
Investment interest calculation, investment maturity period (26 weeks)	182 days
Investment interest calculation, monthly compounding rate	1.00%
Investment interest calculation, minimum annual rate compounded monthly	7.00%
Minimum [Member]
Counterparty fuel mix [Abstract]
Internal generation	50.00%	50.00%
Purchased power	50.00%	50.00%
Maximum [Member]
Counterparty fuel mix [Abstract]
Internal generation	70.00%	70.00%
Purchased power	30.00%	30.00%

Investment maturity period used in deferred compensation interest calculation.

No definition available.

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Minimum annual rate compounded monthly used in deferred compensation interest calculation.

No definition available.

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Percentage increase compounded monthly used in deferred compensation interest calculation.

No definition available.

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Estimate of counterparty's internal generation as a portion of their fuel mix, used as an input to measure fair value.

No definition available.

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Estimate of counterparty's purchased power as a portion of their fuel mix, used as an input to measure fair value.

No definition available.

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Basis adjustment between delivery points for off peak electric future prices. Used as an input to measure fair value.

No definition available.

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Basis adjustment between delivery points for on peak electric future prices. Used as an input to measure fair value.

No definition available.

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