Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating activities
Net income	$ 349,152	$ 860,443
Adjustments to reconcile to cash from operating activities:
Depreciation, depletion and amortization	108,273	98,948
Accretion on asset retirement obligations	15,877	13,290
Deferred income taxes	66,561
Employee stock-based compensation expense	19,699	20,837
Amortization relating to financing activities	1,317	1,958
Gain on disposals and divestitures, net	(714)	(1,012)
Reclamation work completed	(17,642)	(11,229)
Contribution to fund for asset retirement obligations	(4,421)	(110,000)
Changes in:
Receivables	(49,950)	108,635
Inventories	(10,199)	(58,438)
Accounts payable, accrued expenses and other current liabilities	(31,241)	58,791
Income taxes, net	(999)	826
Coal derivative assets and liabilities, including margin account	1,361	5,144
Other	6,744	27,038
Cash provided by operating activities	453,818	1,015,231
Investing activities
Capital expenditures	(121,030)	(94,517)
Minimum royalty payments	(1,113)	(1,069)
Proceeds from disposals and divestitures	1,363	1,963
Purchases of short-term investments	(23,386)	(10,675)
Proceeds from sales of short-term investments	30,417	14,450
Investments in and advances to affiliates, net	(12,210)	(6,692)
Cash used in investing activities	(125,959)	(96,540)
Financing activities
Payments on term loan due 2024	(2,250)	(273,038)
Payments on convertible debt	(58,430)	(149,273)
Net payments on other debt	(30,568)	(23,942)
Debt financing costs		(690)
Purchases of treasury stock	(122,502)	(56,498)
Dividends paid	(183,790)	(264,638)
Payments for taxes related to net share settlement of equity awards	(27,230)	(4,908)
Proceeds from warrants exercised	43,949	19,422
Cash used in financing activities	(380,821)	(753,565)
(Decrease) increase in cash and cash equivalents, including restricted cash	(52,962)	165,126
Cash and cash equivalents, including restricted cash, beginning of period	237,159	326,295
Cash and cash equivalents, including restricted cash, end of period	184,197	491,421
Cash and cash equivalents, including restricted cash, end of period
Cash and cash equivalents	183,097	490,321
Restricted Cash	1,100	1,100
Cash and cash equivalents, including restricted cash	$ 184,197	$ 491,421