Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Cash Flows from Operating Activities:
Net Income	$ 159,952	$ 398,100
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Depreciation, Depletion and Amortization	111,844	124,079
Gain on Sale of Assets	(6,784)	(5,736)
Stock-Based Compensation	7,355	6,785
Amortization of Debt Issuance Costs	1,878	3,389
Loss on Debt Extinguishment	0	2,063
Deferred Income Taxes	180	(561)
Other Adjustments to Net Income	(1,521)	(1,413)
Changes in Operating Assets:
Accounts and Notes Receivable	809	72,470
Inventories	(9,353)	(31,385)
Other Current Assets	3,321	1,773
Changes in Other Assets	(2,070)	(25,654)
Changes in Operating Liabilities:
Accounts Payable	426	(14,810)
Commodity Derivatives, net Liability	0	(15,142)
Other Operating Liabilities	(37,801)	(3,868)
Changes in Other Liabilities	(34,488)	(34,006)
Net Cash Provided by Operating Activities	193,748	476,084
Cash Flows from Investing Activities:
Capital Expenditures	(97,760)	(76,082)
Proceeds from Sales of Assets	6,948	6,239
Investments in Mining-Related Activities	(3,048)	(4,731)
Proceeds from Sales of Short-Term Investments	20,543	30,419
Purchases of Short-Term Investments	(20,084)	(129,757)
Other Investing Activity	(2,100)	0
Net Cash Used in Investing Activities	(95,501)	(173,912)
Cash Flows from Financing Activities:
Payments on Finance Lease Obligations	(6,424)	(13,898)
Payments on Other Debt	(710)	(480)
Shares Withheld for Taxes	(5,578)	(12,746)
Repurchases of Common Stock	(70,879)	(140,519)
Debt-Related Financing Fees	0	(2,684)
Dividends and Dividend Equivalents Paid	(1,098)	(75,474)
Net Cash Used in Financing Activities	(84,689)	(386,454)
Net Increase (Decrease) in Cash and Cash Equivalents and Restricted Cash	13,558	(84,282)
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	256,826	242,670
Non-Cash Investing and Financing Activities:
Finance Lease	364	588
Term Loan B Facility
Cash Flows from Financing Activities:
Payments on debt	0	(63,590)
Senior Secured Second Lien Notes due 2025
Cash Flows from Financing Activities:
Payments on debt	$ 0	$ (77,063)