Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Current Assets:
Cash and Cash Equivalents	$ 412,708	$ 432,174
Accounts and Notes Receivable:
Trade Receivables, net	369,889	349,233
Other Receivables, net	37,071	53,928
Inventories	369,080	374,759
Other Current Assets	82,063	130,128
Total Current Assets	1,270,811	1,340,222
Total Property, Plant and Equipment—Net	4,375,493	4,386,882
Other Assets:
Funds for Asset Retirement Obligations	149,887	148,874
Pension Benefits	51,334	49,618
Other Noncurrent Assets, net	208,396	204,457
Total Other Assets	409,617	402,949
Total Assets	6,055,921	6,130,053
Current Liabilities:
Accounts Payable	315,129	335,623
Current Portion of Long-Term Debt	43,418	98,328
Other Accrued Liabilities	388,425	404,338
Total Current Liabilities	746,972	838,289
Long-Term Liabilities:
Long-Term Debt	411,630	354,160
Postretirement Benefits Other Than Pensions	186,732	186,843
Pneumoconiosis Benefits	258,926	261,201
Asset Retirement Obligations	495,140	496,002
Workers’ Compensation	71,419	70,457
Pension Benefits	20,997	21,111
Deferred Income Taxes	129,819	130,113
Other Noncurrent Liabilities	77,394	93,643
Total Long-Term Liabilities	1,652,057	1,613,530
Total Liabilities	2,399,029	2,451,819
Commitments and Contingent Liabilities (Note 14)
Stockholders' Equity:
Common Stock, $0.01 Par Value; 125,000,000 Shares Authorized, 50,569,806 Shares Issued and Outstanding at March 31, 2026; 50,975,185 Shares Issued and Outstanding at December 31, 2025	506	510
Capital in Excess of Par Value	2,978,068	2,982,077
Retained Earnings	800,652	818,476
Accumulated Other Comprehensive Loss	(122,334)	(122,829)
Total Stockholders’ Equity	3,656,892	3,678,234
Total Liabilities and Stockholders’ Equity	$ 6,055,921	$ 6,130,053