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Other Items and Charges - Additional Information (Detail) - USD ($) $ in Thousands	8 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2015	Apr. 30, 2014	Apr. 30, 2013
Other Items and Charges [Line Items]
Environmental remediation charge	$ 950	$ 0	$ 400
Legal costs for the acquisition	0	0	144	$ 1,410
Development project charge	0	0	1,394
Severance and reorganization charge	$ 0	$ 0	586	3,709
BBI Acquisition [Member]
Other Items and Charges [Line Items]
Legal costs for the acquisition				1,410
Second Lien Notes [Member] | BBI Acquisition [Member]
Other Items and Charges [Line Items]
Legal costs for the acquisition				303
Maine Energy Facility [Member]
Other Items and Charges [Line Items]
Legal costs for the acquisition				505
Development project charge			$ 1,394
Tompkins [Member]
Other Items and Charges [Line Items]
Equity method investment membership interest			50.00%
Legal Costs [Member] | BBI Acquisition [Member]
Other Items and Charges [Line Items]
Legal costs for the acquisition				$ 602
Legal Costs [Member] | Tompkins [Member]
Other Items and Charges [Line Items]
Legal costs for the acquisition			$ 144

X

- Definition

The aggregate amount of significant divestiture and acquisition expenses, along with certain financing costs, recognized during an accounting period that are not disclosed separately. Generally, these items are either unusual or infrequent, but not both.

+ References

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Other Items And Charges [Line Items]

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- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
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- Definition

The charge against earnings in the period for known or estimated future costs arising from requirements to perform environmental remediation activities.

+ References

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The expense charged against earnings to eliminate the capitalized costs of projects that have been terminated during the reporting period, which is added back to net income when calculating cash provided by (used in) operations using the indirect method.

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+ References

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