UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
ASSETS
Cash and cash equivalents	$ 61,844	$ 85,109
Inventories	75,755	77,000
Assets held for sale	7,270	6,466
Federal income tax receivable	845	845
Prepaid insurance	11,248	1,790
Other current assets	19,558	15,499
Total current assets	212,839	231,998
Property, plant and equipment, net	238,906	223,902
Intangibles, net	5,880	6,006
Deferred income taxes	15,113	15,081
Investments in unconsolidated subsidiaries	13,753	12,371
Operating lease right-of-use assets	7,876	8,667
Other non-current assets	43,631	41,683
Total assets	537,998	539,708
LIABILITIES AND EQUITY
Revolving credit agreements	17,000	10,000
Current maturities of long-term debt	4,498	3,953
Asset retirement obligations	13,105	13,114
Accrued payroll	9,069	17,317
Deferred revenue	930	878
Other current liabilities	6,265	7,118
Total current liabilities	63,935	69,986
Long-term debt	28,377	22,003
Operating lease liabilities	7,962	8,782
Asset retirement obligations	38,550	39,499
Pension and other postretirement obligations	5,059	5,183
Liability for uncertain tax positions	5,795	5,795
Other long-term liabilities	6,707	6,120
Total liabilities	156,385	157,368
Common stock:
Capital in excess of par value	29,073	28,672
Retained earnings	354,667	355,873
Accumulated other comprehensive loss	(9,578)	(9,654)
Total stockholders' equity	381,613	382,340
Total liabilities and equity	537,998	539,708
Nonrelated Party
ASSETS
Trade accounts receivable and accounts receivable from affiliates	27,958	37,429
LIABILITIES AND EQUITY
Accounts payable and accounts payable to affiliates	12,377	16,702
Affiliated Entity
ASSETS
Trade accounts receivable and accounts receivable from affiliates	8,361	7,860
LIABILITIES AND EQUITY
Accounts payable and accounts payable to affiliates	691	904
Class A Common Stock
Common stock:
Common stock	5,885	5,883
Class B Common Stock
Common stock:
Common stock	$ 1,566	$ 1,566