CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net income	$ 582	$ 36,456	$ 53,360
Depreciation and amortization	3,973	3,977	3,839
Deferred income taxes	(7,308)	2,291	7,453
Equity in (earnings) losses of Kronos Worldwide, Inc.	15,003	(31,873)	(34,323)
Dividends received from Kronos Worldwide, Inc.	26,766	26,766	25,356
Marketable equity securities	8,156	8,085	(16,229)
Loss on pension plan termination	4,911
Benefit plan expense greater (less) than cash funding	461	130	(220)
Noncash interest income	(3,591)	(267)
Noncash interest expense	695	908	1,116
Other, net	247	(21)	(31)
Change in assets and liabilities:
Accounts and other receivables, net	754	(2,275)	(4,488)
Inventories, net	333	(5,832)	(7,479)
Prepaid expenses and other	42	353	(991)
Accounts payable and accrued liabilities	(12,624)	(10,398)	(9,386)
Accounts with affiliates	578	(662)	279
Accrued environmental remediation and related costs	(1,252)	(582)	(476)
Other noncurrent assets and liabilities, net	(723)	(125)	(171)
Net cash provided by operating activities	37,003	26,931	17,609
Cash flows from investing activities:
Capital expenditures	(1,130)	(3,695)	(4,094)
Purchases	(61,366)	(69,959)
Proceeds from maturities	82,000
Note receivable from affiliate:
Collections	30,500	29,800	40,600
Loans	(27,900)	(24,300)	(29,800)
Other, net		284	2
Net cash provided by (used in) investing activities	22,104	(67,870)	6,708
Cash flows from financing activities:
Dividends paid	(13,672)	(30,753)	(11,712)
Subsidiary treasury stock acquired		(1,744)	(1,311)
Dividends paid to noncontrolling interests in subsidiary	(1,555)	(4,304)	(1,324)
Net cash used in financing activities	(15,227)	(36,801)	(14,347)
Cash and cash equivalents and restricted cash and cash equivalents - net change from:
Operating, investing and financing activities	43,880	(77,740)	9,970
Balance at beginning of year	97,502	175,242	165,272
Balance at end of year	141,382	97,502	175,242
Supplemental disclosures - cash paid (received) for:
Interest	50	34	26
Income taxes, net	$ (300)	$ 1,140	$ 32