CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Current assets:
Cash and cash equivalents	$ 449,027	$ 481,578
Trade accounts receivable, net of allowance for credit losses of $2,260 and $2,396 as of June 30, 2025 and December 31, 2024, respectively	296,046	362,141
Inventories, net	207,251	169,269
Prepaid expenses and other current assets	35,901	23,681
Total current assets	988,225	1,036,669
Property, plant, and equipment, net of accumulated depreciation and amortization of $736,515 and $667,260 as of June 30, 2025 and December 31, 2024, respectively	624,078	634,871
Owned and leased mineral rights, net of accumulated depletion and amortization of $139,719 and $124,965 as of June 30, 2025 and December 31, 2024, respectively	428,362	443,467
Other acquired intangibles, net of accumulated amortization of $44,158 and $41,444 as of June 30, 2025 and December 31, 2024, respectively	37,165	39,879
Long-term restricted cash	126,106	122,583
Long-term restricted investments	42,450	43,131
Deferred income taxes	6,883	6,516
Other non-current assets	119,845	111,592
Total assets	2,373,114	2,438,708
Current liabilities:
Current portion of long-term debt	2,625	2,916
Trade accounts payable	87,412	96,633
Accrued expenses and other current liabilities	153,304	151,560
Total current liabilities	243,341	251,109
Long-term debt	3,144	2,868
Workers’ compensation and black lung obligations	178,778	182,961
Pension obligations	95,888	100,597
Asset retirement obligations	190,043	189,805
Deferred income taxes	28,439	40,486
Other non-current liabilities	19,771	21,385
Total liabilities	759,404	789,211
Commitments and Contingencies (Note 13)
Stockholders’ Equity
Preferred stock - par value $0.01, 5,000,000 shares authorized, none issued	0	0
Common stock - par value $0.01, 50,000,000 shares authorized, 22,437,379 issued and 13,053,823 outstanding at June 30, 2025 and 22,383,325 issued and 13,016,390 outstanding at December 31, 2024	224	224
Additional paid-in capital	845,888	839,804
Accumulated other comprehensive loss	(49,187)	(50,082)
Treasury stock, at cost: 9,383,556 shares at June 30, 2025 and 9,366,935 shares at December 31, 2024	(1,300,700)	(1,296,916)
Retained earnings	2,117,485	2,156,467
Total stockholders’ equity	1,613,710	1,649,497
Total liabilities and stockholders’ equity	$ 2,373,114	$ 2,438,708