Finance Receivables - Special Product (New Neighbor Guaranty program) - Schedule of Delinquent Assessments and Accrued Charges (Detail) - Special Product [Member] - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Accounts Notes And Loans Receivable [Line Items]
Delinquent assessments	$ 1,636,000	$ 2,018,000
Accrued interest and late fees	$ 1,045,000	$ 1,088,000