Workers' Compensation Expense (Schedule of Amounts Recognized in Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accrued Workers' Compensation [Line Items]
Total obligations	$ 173,374	$ 173,340
Less amount included in accrued expenses	18,724	17,584
Noncurrent obligations	154,650	155,756
Occupational disease
Accrued Workers' Compensation [Line Items]
Occupational disease costs	129,218	120,008	$ 167,585
Total workers' compensation expense
Accrued Workers' Compensation [Line Items]
Occupational disease costs	$ 44,156	$ 53,332