CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 138,257	$ 111,522
Restricted cash and cash equivalents	2,919	2,917
Marketable securities	29,662	53,149
Accounts and other receivables, net	17,372	17,101
Receivables from affiliates	601	628
Inventories, net	27,543	30,712
Prepaid expenses and other	1,948	2,235
Total current assets	218,302	218,264
Other assets:
Restricted cash and cash equivalents	27,072	26,943
Note receivable from affiliate	9,800	10,600
Marketable securities	20,577	18,194
Investment in Kronos Worldwide, Inc.	237,221	247,582
Goodwill	27,156	27,156
Other assets, net	3,504	2,060
Total other assets	325,330	332,535
Property and equipment:
Land	5,390	5,390
Buildings	23,262	23,239
Equipment	74,650	74,315
Construction in progress	536	676
Property and equipment, gross	103,838	103,620
Less accumulated depreciation	78,654	77,757
Net property and equipment	25,184	25,863
Total assets	568,816	576,662
Current liabilities:
Accounts payable	3,074	3,148
Accrued litigation settlement	11,887	11,830
Accrued and other current liabilities	7,397	13,182
Accrued environmental remediation and related costs	1,584	1,655
Payables to affiliates	660	634
Total current liabilities	24,602	30,449
Noncurrent liabilities:
Long-term debt from affiliate	500	500
Accrued environmental remediation and related costs	89,363	89,451
Long-term litigation settlement	16,199	16,122
Deferred income taxes	41,439	41,733
Accrued pension costs	1,584	1,571
Other	5,045	5,074
Total noncurrent liabilities	154,130	154,451
NL stockholders' equity:
Preferred stock
Common stock	6,103	6,103
Additional paid-in capital	298,868	298,868
Retained earnings	287,395	284,462
Accumulated other comprehensive loss	(224,240)	(219,621)
Total NL stockholders' equity	368,126	369,812
Noncontrolling interest in subsidiary	21,958	21,950
Total equity	390,084	391,762
Total liabilities and equity	568,816	576,662
Commitments and contingencies (Notes 11 and 13)