New Neighbor Guaranty (NNG) Allowance for Credit Losses - Additional Information (Detail) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses	$ 125,000	$ 125,000
New Neighbor Guaranty (NNG) [Member]
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses	$ 125,000	$ 125,000

A valuation allowance for financing receivables that are expected to be uncollectible.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953423-111524

Name:	us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant