Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash Flows from Operating Activities:
Net Income	$ 498,825	$ 273,962
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Depreciation, Depletion and Amortization	182,871	168,607
Gain on Sale of Assets	(7,082)	(33,094)
Stock-Based Compensation	8,461	6,694
Amortization of Debt Issuance Costs	4,534	6,682
Loss on Debt Extinguishment	2,725	4,361
Deferred Income Taxes	(837)	13,095
Other Adjustments to Net Income	(2,571)	3,880
Changes in Operating Assets:
Accounts and Notes Receivable	37,670	(3,304)
Inventories	(32,096)	(11,685)
Other Current Assets	(4,522)	6,069
Changes in Other Assets	(26,913)	(24,866)
Changes in Operating Liabilities:
Accounts Payable	7,759	41,222
Commodity Derivatives, net Liability	(15,142)	39,282
Other Operating Liabilities	28,751	16,951
Changes in Other Liabilities	(43,615)	(8,170)
Net Cash Provided by Operating Activities	638,818	499,686
Cash Flows from Investing Activities:
Capital Expenditures	(117,749)	(134,456)
Proceeds from Sales of Assets	6,240	19,774
Investments in Mining-Related Activities	(5,366)	0
Proceeds from Sales of Short-Term Investments	83,924	0
Purchases of Short-Term Investments	(162,422)	0
Other Investing Activity	(350)	(1,633)
Net Cash Used in Investing Activities	(195,723)	(116,315)
Cash Flows from Financing Activities:
Payments on Finance Lease Obligations	(19,490)	(18,192)
Payments on Other Debt	(729)	(589)
Shares Withheld for Taxes	(12,746)	(6,187)
Repurchases of Common Stock	(277,382)	0
Debt-Related Financing Fees	(2,810)	(7,766)
Dividends	(75,474)	(34,871)
Net Cash Used in Financing Activities	(554,053)	(260,929)
Net (Decrease) Increase in Cash and Cash Equivalents and Restricted Cash	(110,958)	122,442
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	215,994	320,648
Non-Cash Investing and Financing Activities:
Finance Lease	588	6,256
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)	(125,687)
Senior Secured Second Lien Notes due 2025
Cash Flows from Financing Activities:
Payments on debt	$ (101,832)	$ (26,387)