Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash Flows from Operating Activities:
Net Income	$ 101,891	$ 230,377
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Depreciation, Depletion and Amortization	56,997	59,551
Gain on Sale of Assets	(6,077)	(5,726)
Stock-Based Compensation	5,118	4,792
Amortization of Debt Issuance Costs	937	2,141
Loss on Debt Extinguishment	0	1,375
Deferred Income Taxes	74	(210)
Other Adjustments to Net Income	(776)	(34)
Changes in Operating Assets:
Accounts and Notes Receivable	(19,618)	11,031
Inventories	(21,336)	(29,345)
Other Current Assets	2,414	5,306
Changes in Other Assets	(1,382)	(4,810)
Changes in Operating Liabilities:
Accounts Payable	3,180	(3,274)
Commodity Derivatives, net Liability	0	(15,142)
Other Operating Liabilities	(26,065)	21,888
Changes in Other Liabilities	(17,873)	(29,409)
Net Cash Provided by Operating Activities	77,484	248,511
Cash Flows from Investing Activities:
Capital Expenditures	(42,352)	(33,757)
Proceeds from Sales of Assets	6,191	6,000
Investments in Mining-Related Activities	(23)	0
Proceeds from Sales of Short-Term Investments	15,543	0
Purchases of Short-Term Investments	(15,331)	(75,000)
Other Investing Activity	(325)	0
Net Cash Used in Investing Activities	(36,297)	(102,757)
Cash Flows from Financing Activities:
Payments on Finance Lease Obligations	(3,410)	(8,137)
Payments on Other Debt	(253)	(235)
Shares Withheld for Taxes	(5,551)	(12,708)
Repurchases of Common Stock	(57,881)	(75,121)
Dividends and Dividend Equivalents Paid	(582)	(38,287)
Net Cash Used in Financing Activities	(67,677)	(225,863)
Net Decrease in Cash and Cash Equivalents and Restricted Cash	(26,490)	(80,109)
Cash and Cash Equivalents and Restricted Cash at Beginning of Period	243,268	326,952
Cash and Cash Equivalents and Restricted Cash at End of Period	216,778	246,843
Non-Cash Investing and Financing Activities:
Finance Lease	0	588
Term Loan B Facility
Cash Flows from Financing Activities:
Payments on debt	0	(40,000)
Senior Secured Second Lien Notes due 2025
Cash Flows from Financing Activities:
Payments on debt	$ 0	$ (51,375)