Changes in Initial Product Warranty Accrual and Expenses Under Initial and Extended Warranties (Detail) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Movement in Standard Product Warranty Accrual | |||
| Initial warranty accrual, beginning balance | $ 2,188 | $ 1,449 | $ 1,096 |
| Provision for estimated warranty cost | 348 | 1,715 | 1,214 |
| Warranty expenditures | (830) | (976) | (861) |
| Initial warranty accrual, ending balance | 1,706 | 2,188 | 1,449 |
| Less warranty accrual, long-term | 773 | 843 | 519 |
| Total warranty accrual, current portion | $ 933 | $ 1,345 | $ 930 |