CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net income	$ 161.3	$ 5.1	$ 133.1
Depreciation and amortization	66.7	54.1	58.5
Gain on remeasurement of investment in TiO2 manufacturing joint venture	(64.5)
Premium on issuance of senior secured notes	6.0
Deferred income taxes	43.5	(50.3)	3.6
Benefit plan expense greater (less) than cash funding	(8.1)	(6.2)	8.6
Loss on pension plan termination		6.2
Water system fixed asset impairment			16.4
Fixed asset impairment		3.8
Noncash interest expense	3.1	2.0	2.2
Distributions from (contributions to) TiO2 manufacturing joint venture, net	(2.7)	3.1	(10.5)
Gain from sale of land	(0.5)	(1.5)
Other, net	(0.2)	5.2	12.1
Change in assets and liabilities:
Accounts and other receivables, net	(16.7)	(44.6)	81.1
Inventories, net	(41.0)	56.7	(204.2)
Land held for development, net	5.3	0.8	21.4
Accounts payable and accrued liabilities	(60.2)	11.2	3.9
Income taxes	9.2	9.3	(0.5)
Accounts with affiliates	(6.6)	(27.8)	9.4
Other noncurrent assets	(29.5)	(9.5)	(3.4)
Other noncurrent liabilities	(15.1)	(19.3)	(83.9)
Other, net	(6.0)	5.6	(12.9)
Net cash provided by operating activities	44.0	3.9	34.9
Cash flows from investing activities:
Capital expenditures	(30.9)	(48.5)	(67.6)
Acquisition of remaining TiO2 manufacturing joint venture interest, net of cash acquired	(156.8)
Cash, cash equivalents and restricted cash of BWC	2.6		(8.6)
Purchases of marketable securities	(2.7)	(66.4)	(73.6)
Proceeds from disposal of marketable securities	57.0	85.7	2.9
Proceeds from land sales	5.6	1.8
Other, net	0.2	(1.6)	0.2
Net cash used in investing activities	(125.0)	(29.0)	(146.7)
Cash flows from financing activities:
Borrowings	158.6
Payments	(148.9)
Payments on long-term debt	(102.2)	(29.8)	(62.0)
Kronos term loan from Contran	53.7
Proceeds from issuance of Kronos senior secured notes	80.2
Deferred financing fees	(9.3)
Valhi cash dividends paid	(9.1)	(9.1)	(9.0)
Distributions to noncontrolling interest in subsidiaries	(25.3)	(34.0)	(38.9)
Subsidiary treasury stock acquired		(2.9)	(4.0)
Other, net		(0.1)	(0.1)
Net cash used in financing activities	(2.3)	(75.9)	(114.0)
Cash, cash equivalents and restricted cash and cash equivalents - net change from:
Operating, investing and financing activities	(83.3)	(101.0)	(225.8)
Effect of exchange rates on cash	(0.1)	1.0	(5.1)
Balance at beginning of year	462.0	562.0	792.9
Balance at end of year	378.6	462.0	562.0
Cash paid for:
Interest, net of amounts capitalized	45.1	26.6	25.8
Income taxes, net	41.8	27.4	43.7
Noncash investing activities:
Change in accruals for capital expenditures	$ 7.0	$ 1.1	$ 6.6