Fair Value Measurements (Details Textual) (USD $)	6 Months Ended
Sep. 30, 2014
Fair Value Measurements [Abstract]
Derivatives, unit per hour	$ 1
Level 3 Instruments [Member]
Fair Value Measurements [Abstract]
Unrealized losses related to financial instruments	$ 2,000,000
Electricity swaps [Member]
Fair Value Measurements [Abstract]
Average forward price (per megawatt hour)	59
Premium over forward prices in nearby observable market (per megawatt hour)	7
Actual swap settlement price (per megawatt hour)	43
Decrease in valuation per $1 per megawatt hour decline in electricity price	1

Premium per unit over forward prices in observable market.

No definition available.

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- Definition

Represents the estimated average forward price per unit.

+ References

No definition available.

+ Details

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- Definition

Derivatives, unit per megawatt hour decline

+ References

No definition available.

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- Definition

The forward price on the price risk forward or futures contract, such as a gas futures contract.

+ References

No definition available.

+ Details

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- Details

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- Definition

Amount of realized and unrealized gain (loss) included in earnings, which have arisen from the use of significant unobservable inputs (level 3) to measure fair value of assets, liabilities, and financial instruments classified in shareholders' equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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- Definition

Description of the sensitivity of the fair value measurements to changes in unobservable inputs and the inter-relationships between those inputs as well as how those inter-relationships might magnify or mitigate the effect of changes in the unobservable inputs on the fair value measurements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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