Workers Compensation Expense - Worker's compensation expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Total workers' compensation expense
Accrued Workers' Compensation [Line Items]
Total workers' compensation expense	$ 5,324	$ 3,953
Occupational disease
Accrued Workers' Compensation [Line Items]
Service cost	1,278	993
Interest cost	1,565	1,511
Amortization of other actuarial (gains)	(3)	(241)
Net benefit credit	2,840	2,263
Traumatic injury claims and assessments
Accrued Workers' Compensation [Line Items]
Traumatic injury claims and assessments	$ 2,484	$ 1,690