CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net income	$ 69,261	$ 582	$ 36,456
Depreciation and amortization	3,691	3,973	3,977
Deferred income taxes	13,718	(7,308)	2,291
Equity in (earnings) losses of Kronos Worldwide, Inc.	(26,381)	15,003	(31,873)
Dividends received from Kronos Worldwide, Inc.	16,905	26,766	26,766
Marketable equity securities (gain) loss	(9,821)	8,156	8,085
Loss on pension plan termination		4,911
Benefit plan expense greater than cash funding	397	461	130
Noncash interest income	(817)	(3,591)	(267)
Noncash interest expense	479	695	908
Other, net	217	247	(21)
Change in assets and liabilities:
Accounts and other receivables, net	(6,679)	754	(2,275)
Inventories, net	2,126	333	(5,832)
Prepaid expenses and other	82	42	353
Accounts payable and accrued liabilities	(13,256)	(12,624)	(10,398)
Accounts with affiliates	700	578	(662)
Accrued environmental remediation and related costs	(21,828)	(1,252)	(582)
Other noncurrent assets and liabilities, net	(3,220)	(723)	(125)
Net cash provided by operating activities	25,574	37,003	26,931
Cash flows from investing activities:
Capital expenditures	(1,432)	(1,130)	(3,695)
Marketable securities:
Purchases		(61,366)	(69,959)
Proceeds from maturities	54,000	82,000
Note receivable from affiliate:
Collections	26,300	30,500	29,800
Loans	(25,000)	(27,900)	(24,300)
Proceeds from land sale	5,000
Other, net			284
Net cash provided by (used in) investing activities	58,868	22,104	(67,870)
Cash flows from financing activities:
Dividends paid	(36,634)	(13,672)	(30,753)
Subsidiary treasury stock acquired			(1,744)
Dividends paid to noncontrolling interests in subsidiary	(5,000)	(1,555)	(4,304)
Net cash used in financing activities	(41,634)	(15,227)	(36,801)
Cash and cash equivalents and restricted cash and cash equivalents - net change from:
Operating, investing and financing activities	42,808	43,880	(77,740)
Balance at beginning of year	141,382	97,502	175,242
Balance at end of year	184,190	141,382	97,502
Cash paid (received) for:
Interest	51	50	34
Income taxes, net	127	(300)	1,140
Noncash investing activities -
Change in accruals for capital expenditures	$ 423	$ 23	$ (49)