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Summary of Significant Accounting Policies - Asset Impairments - Additional Information (Detail) - USD ($)	8 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2015	Apr. 30, 2014	Apr. 30, 2013
Summary Of Significant Accounting Policies [Line Items]
Goodwill impairment incurred	$ 0	$ 0	$ 0	$ 0
Investment impairment charge	2,320,000	2,099,000
Carrying amount of cost method investment	14,432,000	$ 12,333,000	$ 16,752,000
Recycle Rewards Inc [Member]
Summary Of Significant Accounting Policies [Line Items]
Outstanding common stock percentage		5.30%
Investment impairment charge	$ 2,320,000	$ 1,090,000
Carrying amount of cost method investment		$ 1,070,000
GreenerU Inc [Member]
Summary Of Significant Accounting Policies [Line Items]
Outstanding common stock percentage		9.80%
Investment impairment charge		$ 691,000
Carrying amount of cost method investment		$ 309,000
Agreen Energy LLC [Member]
Summary Of Significant Accounting Policies [Line Items]
Outstanding common stock percentage		17.00%
Bgreen Energy LLC [Member]
Summary Of Significant Accounting Policies [Line Items]
Outstanding common stock percentage		16.20%
Agreen And Bgreen [Member]
Summary Of Significant Accounting Policies [Line Items]
Investment impairment charge		$ 318,000
Carrying amount of cost method investment		$ 297,000
Eastern Region [Member]
Summary Of Significant Accounting Policies [Line Items]
Reporting units exceeded their carrying values		22.90%
Western Region [Member]
Summary Of Significant Accounting Policies [Line Items]
Reporting units exceeded their carrying values		22.90%
Recycling [Member]
Summary Of Significant Accounting Policies [Line Items]
Reporting units exceeded their carrying values		22.90%
Other [Member] | Customer Solutions [Member]
Summary Of Significant Accounting Policies [Line Items]
Reporting units exceeded their carrying values		22.90%

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Amount, after adjustment, of cost-method investment. Adjustments include, but are not limited to, dividends received in excess of earnings after date of investment that are considered a return of investment and other than temporary impairments.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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