Earnings Per Share - Reconciliation of Basic and Diluted Weighted Average Shares Outstanding (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2019 |
Sep. 27, 2019 |
Jun. 28, 2019 |
Mar. 29, 2019 |
Dec. 31, 2018 |
Sep. 28, 2018 |
Jun. 29, 2018 |
Mar. 30, 2018 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||||||||||
| Net income | $ 10,626 | $ 9,382 | $ 7,617 | $ 7,091 | $ 10,124 | $ 9,866 | $ 9,195 | $ 6,111 | $ 34,716 | $ 35,296 | $ 59,497 |
| Weighted average common shares outstanding - basic (in shares) | 11,515 | 11,506 | 11,455 | 11,292 | 11,262 | 11,248 | 11,235 | 11,146 | 11,444 | 11,224 | 11,021 |
| Add: Dilutive impact of stock options (in shares) | 47 | 63 | 67 | ||||||||
| Weighted average number of shares outstanding - diluted (in shares) | 11,728 | 11,678 | 11,605 | 11,399 | 11,369 | 11,406 | 11,383 | 11,338 | 11,612 | 11,378 | 11,209 |
| Basic earnings per share (in dollars per share) | $ 0.92 | $ 0.82 | $ 0.66 | $ 0.63 | $ 0.90 | $ 0.88 | $ 0.82 | $ 0.55 | $ 3.03 | $ 3.14 | $ 5.40 |
| Diluted earnings per share (in dollars per share) | $ 0.91 | $ 0.80 | $ 0.66 | $ 0.62 | $ 0.89 | $ 0.86 | $ 0.81 | $ 0.54 | $ 2.99 | $ 3.10 | $ 5.31 |
| Anti-dilutive restricted stock units | |||||||||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||||||||||
| Add: Dilutive impact of restricted stock units (in shares) | 121 | 91 | 121 | ||||||||