Workers' Compensation Expense (Schedule of Amounts Recognized in Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accrued Workers' Compensation [Line Items]
Total obligations	$ 173,340	$ 238,307
Less amount included in accrued expenses	17,584	14,202
Noncurrent obligations	155,756	224,105
Occupational disease
Accrued Workers' Compensation [Line Items]
Occupational disease costs	120,008	167,585	$ 183,001
Total workers' compensation expense
Accrued Workers' Compensation [Line Items]
Occupational disease costs	$ 53,332	$ 70,722