Accrued Expenses (Activity Related to Warranties) (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 29, 2018 |
Jun. 30, 2017 |
Jun. 29, 2018 |
Jun. 30, 2017 |
|
| Movement in Standard Product Warranty Accrual [Roll Forward] | ||||
| Beginning warranty liability | $ 6,596 | $ 5,003 | $ 6,481 | $ 4,593 |
| Charge to cost of sales | 503 | 1,391 | 1,797 | 3,053 |
| Costs incurred | (957) | (1,317) | (2,136) | (2,569) |
| Ending warranty liability | $ 6,142 | $ 5,077 | $ 6,142 | $ 5,077 |