Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash Flows from Operating Activities:
Net Income	$ 398,100	$ 121,841
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Depreciation, Depletion and Amortization	124,079	113,834
Gain on Sale of Assets	(5,736)	(6,546)
Stock-Based Compensation	6,785	5,470
Amortization of Debt Issuance Costs	3,389	3,980
Loss on Debt Extinguishment	2,063	3,687
Deferred Income Taxes	(561)	(7,762)
Other Adjustments to Net Income	(1,413)	291
Changes in Operating Assets:
Accounts and Notes Receivable	72,470	(33,585)
Inventories	(31,385)	(5,567)
Other Current Assets	1,773	6,845
Changes in Other Assets	(25,654)	(10,356)
Changes in Operating Liabilities:
Accounts Payable	(14,810)	29,053
Commodity Derivatives, net Liability	(15,142)	122,724
Other Operating Liabilities	(3,868)	5,066
Changes in Other Liabilities	(34,006)	(2,417)
Net Cash Provided by Operating Activities	476,084	346,558
Cash Flows from Investing Activities:
Capital Expenditures	(76,082)	(76,061)
Proceeds from Sales of Assets	6,239	7,418
Investments in Mining-Related Activities	(4,731)	0
Proceeds from Sales of Short-Term Investments	30,419	0
Purchases of Short-Term Investments	(129,757)	0
Other Investing Activity	0	(1,483)
Net Cash Used in Investing Activities	(173,912)	(70,126)
Cash Flows from Financing Activities:
Payments on Finance Lease Obligations	(13,898)	(12,086)
Payments on Other Debt	(480)	(375)
Shares Withheld for Taxes	(12,746)	(6,194)
Repurchases of Common Stock	(140,519)	0
Debt-Related Financing Fees	(2,684)	0
Dividends	(75,474)	0
Net Cash Used in Financing Activities	(386,454)	(161,979)
Net (Decrease) Increase in Cash and Cash Equivalents and Restricted Cash	(84,282)	114,453
Cash and Cash Equivalents and Restricted Cash at Beginning of Period	326,952	198,206
Cash and Cash Equivalents and Restricted Cash at End of Period	242,670	312,659
Non-Cash Investing and Financing Activities:
Finance Lease	588	4,166
Term Loan A Facility
Cash Flows from Financing Activities:
Payments on debt	0	(41,250)
Term Loan B Facility
Cash Flows from Financing Activities:
Payments on debt	(63,590)	(75,687)
Senior Secured Second Lien Notes due 2025
Cash Flows from Financing Activities:
Payments on debt	$ (77,063)	$ (26,387)