| Summary of changes in goodwill | A summary of changes in goodwill by segment for the years ended December 28, 2019 and December 29, 2018 is as follows: 
|   |   | Hydraulics |   |   | Electronics |   |   | Total |   |  
| Balance at December 30, 2017 |   | $ | 2,496 |   |   | $ | 106,373 |   |   | $ | 108,869 |   |  
| Acquisition of Faster |   |   | 288,792 |   |   |   | — |   |   |   | 288,792 |   |  
| Acquisition of Custom Fluidpower |   |   | 5,111 |   |   |   | — |   |   |   | 5,111 |   |  
| Currency translation |   |   | (19,641 | ) |   |   | — |   |   |   | (19,641 | ) |  
| Balance at December 29, 2018 |   | $ | 276,758 |   |   | $ | 106,373 |   |   | $ | 383,131 |   |  
| Faster acquisition measurement period adjustment |   |   | (343 | ) |   |   | — |   |   |   | (343 | ) |  
| Custom Fluidpower acquisition measurement period adjustment |   |   | 1,205 |   |   |   | — |   |   |   | 1,205 |   |  
| Currency translation |   |   | (6,424 | ) |   |   | — |   |   |   | (6,424 | ) |  
| Balance at December 28, 2019 |   | $ | 271,196 |   |   | $ | 106,373 |   |   | $ | 377,569 |   |    | 
| Schedule of intangible assets | At December 28, 2019 and December 29, 2018, intangible assets consisted of the following:   
|   |   |   |   | December 28, 2019 |   |   | December 29, 2018 |   |  
|   |   | Useful life (years) |   | Gross carrying amount |   |   | Accumulated amortization |   |   | Net carrying amount |   |   | Gross carrying amount |   |   | Accumulated amortization |   |   | Net carrying amount |   |  
| Definite-lived intangibles: |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |  
| Trade names and brands |   | 10-20 |   | $ | 56,032 |   |   | $ | (7,658 | ) |   | $ | 48,374 |   |   | $ | 56,604 |   |   | $ | (4,712 | ) |   | $ | 51,892 |   |  
| Non-compete agreements |   | 5 |   |   | 950 |   |   |   | (586 | ) |   |   | 364 |   |   |   | 950 |   |   |   | (396 | ) |   |   | 554 |   |  
| Technology |   | 7 - 13 |   |   | 31,704 |   |   |   | (8,661 | ) |   |   | 23,043 |   |   |   | 32,004 |   |   |   | (5,488 | ) |   |   | 26,516 |   |  
| Supply agreement |   | 10 |   |   | 21,000 |   |   |   | (6,475 | ) |   |   | 14,525 |   |   |   | 21,000 |   |   |   | (4,375 | ) |   |   | 16,625 |   |  
| Customer relationships |   | 15 - 26 |   |   | 227,844 |   |   |   | (19,499 | ) |   |   | 208,345 |   |   |   | 232,275 |   |   |   | (10,168 | ) |   |   | 222,107 |   |  
| Licensing agreement |   | 15 |   |   | — |   |   |   | — |   |   |   | — |   |   |   | 3,716 |   |   |   | (862 | ) |   |   | 2,854 |   |  
|   |   |   |   | $ | 337,530 |   |   | $ | (42,879 | ) |   | $ | 294,651 |   |   | $ | 346,549 |   |   | $ | (26,001 | ) |   | $ | 320,548 |   |    | 
| Schedule of estimated amortization expense of intangible assets | Amortization expense for the 2019, 2018 and 2017 fiscal years was approximately $18,065, $23,262 and $8,423, respectively. Future estimated amortization expense is presented below.   
| Year: |   |   |   |   |  
| 2020 |   | $ | 17,875 |   |  
| 2021 |   |   | 17,775 |   |  
| 2022 |   |   | 17,512 |   |  
| 2023 |   |   | 17,453 |   |  
| 2024 |   |   | 16,798 |   |  
| Thereafter |   |   | 207,238 |   |  
| Total |   | $ | 294,651 |   |  |