Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
ASSETS
Cash and cash equivalents	$ 97,113	$ 86,005
Trade accounts receivable	32,143	25,667
Accounts receivable from affiliates	6,427	5,605
Inventories	56,956	54,085
Refundable federal income taxes	3,919	15,054
Prepaid insurance	7,766	2,016
Other current assets	14,252	14,621
Total current assets	218,576	203,053
Property, plant and equipment, net	210,470	193,167
Intangibles, net	29,868	31,774
Operating lease right-of-use assets	8,250	8,911
Other non-current assets	47,019	46,225
Total assets	547,344	507,220
LIABILITIES AND EQUITY
Accounts payable	16,490	12,208
Accounts payable to affiliates	885	741
Current maturities of long-term debt	2,929	2,527
Asset retirement obligations	1,820	1,820
Accrued payroll	11,281	16,339
Deferred revenue	1,803	4,082
Other current liabilities	8,430	8,299
Total current liabilities	43,638	46,016
Long-term debt	15,498	18,183
Operating lease liabilities	9,214	9,733
Asset retirement obligations	42,873	42,131
Pension and other postretirement obligations	5,422	6,605
Deferred income taxes	10,808	14,792
Liability for uncertain tax positions	10,113	10,113
Other long-term liabilities	7,175	7,531
Total liabilities	144,741	155,104
Common stock:
Capital in excess of par value	19,634	16,331
Retained earnings	383,574	336,778
Accumulated other comprehensive loss	(7,940)	(8,176)
Total stockholders' equity	402,603	352,116
Total liabilities and equity	547,344	507,220
Unconsolidated Subsidiaries
ASSETS
Investments in unconsolidated subsidiaries	15,379	19,090
Private Company Equity
ASSETS
Investments in unconsolidated subsidiaries	17,782	5,000
Class A Common Stock
Common stock:
Common stock	5,769	5,616
Class B Common Stock
Common stock:
Common stock	$ 1,566	$ 1,567