Receivables - Receivables (Detail) - USD ($) $ in Thousands |
Mar. 31, 2018 |
Dec. 31, 2017 |
---|---|---|
Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
Total | $ 4,586 | $ 6,333 |
Allowance for bad debts | (26) | (26) |
Receivables, net | 4,560 | 6,307 |
Receivables and accrued interest | ||
Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
Total | 1,416 | 2,557 |
Notes receivable | ||
Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
Total | $ 3,170 | $ 3,776 |
Average interest rates | 5.40% | 5.40% |