Fixed Assets - Additional Information (Detail) - USD ($)	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014
Utilities Operating Expense, Depreciation and Amortization	$ 212,000	$ 169,000

Amount of operating expense for depreciation and amortization of regulated operation.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(b))
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration