Components of Accounts Receivable, Net of Allowance (Detail) - USD ($) $ in Thousands |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Components of accounts receivable, net of allowances | ||
| Trade | $ 9,699 | $ 8,850 |
| Royalties | 62 | 61 |
| Other | 23 | 37 |
| Total receivables, net | $ 9,784 | $ 8,948 |