Description of Business and Summary of Significant Accounting Policies - Immaterial Restatement of Prior Period Balances (Details) - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 9 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Oct. 02, 2020 |
Jul. 03, 2020 |
Apr. 03, 2020 |
Dec. 31, 2019 |
Sep. 27, 2019 |
Jun. 28, 2019 |
Mar. 29, 2019 |
Oct. 02, 2020 |
Sep. 27, 2019 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Error Corrections and Prior Period Adjustments Restatement [Line Items] | ||||||||||||
| Decrease in retained earnings | $ (205,245) | $ (185,075) | $ (205,245) | $ (185,075) | ||||||||
| Net income | $ (10,391) | $ (1,111) | $ (8,668) | $ (7,841) | $ (7,617) | $ (7,074) | $ (20,170) | $ (22,532) | ||||
| Decrease in diluted earnings per share (in dollars per share) | $ (0.88) | $ (0.67) | $ (1.72) | $ (1.95) | ||||||||
| Correction | ||||||||||||
| Error Corrections and Prior Period Adjustments Restatement [Line Items] | ||||||||||||
| Decrease in retained earnings | $ 2,516 | 2,516 | ||||||||||
| Net income | $ 1,541 | $ 0 | $ 17 | $ 1,558 | $ 1,500 | |||||||
| Decrease in diluted earnings per share (in dollars per share) | $ 0.00 | $ 0.13 | $ 0.00 | $ 0.00 | $ 0.13 | $ 0.13 | $ 0.02 | $ 0.01 | ||||