Summary of significant accounting policies - Post-employment Benefits (Details) - USD ($) |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
|
Accounting Policies [Abstract] | |||
Employer contribution, percentage | 8.33% | ||
Severance pay | $ 5,537,000 | $ 4,096,000 | $ 2,436,000 |
Maximum contribution percent of pretax salary (up to) | 50.00% | ||
Maximum amount of contribution per employee | $ 20,500 | ||
Additional contribution amount for employees over 50 | $ 6,500 | ||
Employee contribution match, percent | 100.00% | ||
Employer contribution percent of salary, maximum, percent | 4.00% | ||
Company's matching contribution amount | $ 873,000 | $ 656,000 | $ 395,000 |