Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
ASSETS
Cash and cash equivalents	$ 81,620	$ 86,005
Trade accounts receivable	27,226	25,667
Accounts receivable from affiliates	5,804	5,605
Inventories	55,967	54,085
Refundable federal income taxes	12,537	15,054
Prepaid insurance	11,283	2,016
Other current assets	12,215	14,621
Total current assets	206,652	203,053
Property, plant and equipment, net	196,463	193,167
Intangibles, net	30,927	31,774
Investments in unconsolidated subsidiaries	18,452	19,090
Operating lease right-of-use assets	8,583	8,911
Other non-current assets	51,930	51,225
Total assets	513,007	507,220
LIABILITIES AND EQUITY
Accounts payable	11,037	12,208
Accounts payable to affiliates	909	741
Current maturities of long-term debt	2,965	2,527
Asset retirement obligations	1,820	1,820
Accrued payroll	8,040	16,339
Deferred revenue	2,989	4,082
Other current liabilities	8,664	8,299
Total current liabilities	36,424	46,016
Long-term debt	22,573	18,183
Operating lease liabilities	9,478	9,733
Asset retirement obligations	42,278	42,131
Pension and other postretirement obligations	6,001	6,605
Deferred income taxes	14,303	14,792
Liability for uncertain tax positions	10,113	10,113
Other long-term liabilities	7,343	7,531
Total liabilities	148,513	155,104
Common stock:
Capital in excess of par value	17,309	16,331
Retained earnings	347,915	336,778
Accumulated other comprehensive loss	(8,058)	(8,176)
Total stockholders' equity	364,494	352,116
Total liabilities and equity	513,007	507,220
Class A Common Stock
Common stock:
Common stock	5,762	5,616
Class B Common Stock
Common stock:
Common stock	$ 1,566	$ 1,567