Workers Compensation Expense - Worker's compensation expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Total workers' compensation (credit) expense
Accrued Workers' Compensation [Line Items]
Total workers' compensation (credit) expense	$ 5,780	$ (4,571)	$ 16,537	$ 4,385
Occupational disease
Accrued Workers' Compensation [Line Items]
Service cost	1,278	993	3,833	2,980
Interest cost	1,565	1,511	4,696	4,531
Amortization of other actuarial (gains)	(3)	(241)	(8)	(723)
Net benefit credit	2,840	2,263	8,521	6,788
Traumatic injury claims and assessments
Accrued Workers' Compensation [Line Items]
Traumatic injury claims and assessments	$ 2,940	$ (6,834)	$ 8,016	$ (2,403)