Employee Retirement Plans - Pension expense (Details) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2023
USD ($)
item
|
Dec. 31, 2022
USD ($)
|
Dec. 31, 2021
USD ($)
|
|
| Employee Retirement Plans | |||
| Number of regional multi-employer pension plans in which the entity participates | item | 56 | ||
| Defined contribution plans | $ 18,710 | $ 17,946 | $ 12,192 |
| Multi-employer plans | 12,475 | 12,788 | 12,308 |
| Total expense related to participation in retirement plans | $ 31,185 | $ 30,734 | $ 24,500 |