Approximate annual increase in revenues based on adjusted base period volumes.

No definition available.

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Increased investments covered by change application.

No definition available.

Interim increase (decrease), percent.

No definition available.

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Amount of public utility's approved rate increase (decrease) by regulatory agency.

No definition available.

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Amount of public utility's interim rate increase (decrease) allowed while waiting final decision of regulatory agency.

No definition available.

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Amount of public utility's requested rate increase (decrease) with regulatory agency.

No definition available.

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Percentage of public utility's requested rate increase (decrease) with regulatory agency.

No definition available.

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Regulatory matters and revenues subject to refund (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended
	Feb. 27, 2014 NDPSC [Member]	Nov. 17, 2013 NDPSC [Member]	Sep. 18, 2013 NDPSC [Member]	Oct. 31, 2013 FERC [Member]	Jul. 10, 2014 Subsequent event [Member] NDPSC [Member]
Regulatory matters and revenues subject to refund [Line Items]
Annual amount recovered					$ 8.6
Rate increase requested	7.4		6.8
Percent above current rates requested	4.60%		6.40%
Interim rate increase (decrease), amount		4.3
Interim rate increase, percent		4.00%
Increased expenditures covered by change application				312
Approximate annual increase in revenues				$ 11.5