The maximum percentage of the natural gas portfolio that is fixed

No definition available.

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- Definition

Estimated period for the anticipated transfer of gain (loss), net, from accumulated other comprehensive income into earnings, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Details

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- Definition

Date the derivative contract matures, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

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- Definition

Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 10A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=28358780&loc=SL7669646-108580

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- Definition

The cash outflow for a financial contract that meets the hedge criteria as either cash flow hedge, fair value hedge or hedge of net investment in foreign operations.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 27

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3581-108585

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Derivatives and Fair Value Measurements - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Derivative [Line Items]
Natural gas portfolios, maximum % rate			35.00%
Gains (losses) recognized in income or other comprehensive income for derivative designated cash flow hedges	$ 519,000	$ 519,000	$ 1,037,000	$ 1,037,000	$ 2,074,000	$ 2,074,000
Derivative instrument loss at settlement amortization period			10 years
Minimum [Member]
Derivative [Line Items]
Maturities of natural gas swaps			Jul. 01, 2014
Maximum [Member]
Derivative [Line Items]
Maturities of natural gas swaps			Mar. 01, 2016
Cash flow hedging [Member]
Derivative [Line Items]
Gains (losses) recognized in income or other comprehensive income for derivative designated cash flow hedges			0
Settlement at maturity of the first FSIRS [Member]
Derivative [Line Items]
Agreement settlement paid			11,700,000
Settlement at maturity of the second FSIRS [Member]
Derivative [Line Items]
Agreement settlement paid			$ 21,800,000