Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 85,257	$ 101,600
Trade accounts receivable, net of allowances of $1,523 in 2018 and 2017	20,817	14,611
Accounts receivable from affiliates	7,999	19,919
Inventories	31,209	30,015
Assets held for sale	4,330	0
Prepaid expenses and other	14,562	10,843
Total current assets	164,174	176,988
Property, plant and equipment, net	124,554	120,068
Intangibles, net	40,516	43,554
Deferred income taxes	0	5,962
Investment in unconsolidated subsidiaries	20,091	16,335
Deferred costs	3,244	3,582
Other non-current assets	24,412	23,063
Total assets	376,991	389,552
Current liabilities
Accounts payable	7,746	7,575
Accounts payable to affiliates	1,653	1,925
Revolving credit agreements	4,000	15,000
Current maturities of long-term debt	654	1,125
Asset retirement obligations	1,826	3,092
Accrued payroll	19,853	17,204
Other current liabilities	6,516	8,055
Total current liabilities	42,248	53,976
Long-term debt	6,367	42,021
Asset retirement obligations	35,877	37,005
Pension and other postretirement obligations	10,429	11,827
Deferred income taxes	2,846	0
Deferred compensation	12,939	12,939
Other long-term liabilities	15,581	12,336
Total liabilities	126,287	170,104
Common stock:
Capital in excess of par value	7,042	4,447
Retained earnings	250,352	216,490
Accumulated other comprehensive loss	(13,611)	(8,341)
Total stockholders’ equity	250,704	219,448
Total liabilities and equity	376,991	389,552
Class A Common Stock
Common stock:
Common stock	5,352	5,282
Class B Common Stock
Common stock:
Common stock	$ 1,569	$ 1,570