CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net income (loss)	$ (49.1)	$ 104.5	$ 112.9
Depreciation	48.6	51.7	51.3
Amortization of operating lease right-of-use assets	4.5	4.5	6.6
Deferred income taxes	(39.3)	(1.4)	14.3
Benefit plan expense greater (less) than cash funding	(5.1)	8.7	11.9
Marketable equity securities	1.0	1.0	(2.0)
Distributions from (contributions to) TiO2 manufacturing joint venture, net	3.1	(10.5)	3.8
Fixed asset impairment	3.8
Other, net	1.8	3.5	0.8
Change in assets and liabilities:
Accounts and other receivables, net	(43.9)	85.7	(58.6)
Inventories, net	56.3	(198.4)	65.8
Prepaid expenses	6.3	(12.5)	(20.5)
Accounts payable and accrued liabilities	33.9	36.7	47.2
Income taxes	8.2	(0.1)	(1.6)
Accounts with affiliates	(26.0)	8.7	(26.3)
Other noncurrent assets	0.8	0.3	(5.1)
Other noncurrent liabilities	0.6	(0.7)	6.0
Net cash provided by operating activities	5.5	81.7	206.5
Cash flows from investing activities:
Capital expenditures	(47.4)	(63.2)	(58.6)
Other		0.1
Net cash used in investing activities	(47.4)	(63.1)	(58.6)
Cash flows from financing activities:
Payments on long-term debt	(1.1)	(1.3)	(1.4)
Deferred financing fees	(0.1)	(0.1)	(1.9)
Dividends paid	(87.5)	(87.8)	(83.2)
Treasury stock acquired	(2.9)	(2.3)	(0.2)
Net cash used in financing activities	(91.6)	(91.5)	(86.7)
Cash, cash equivalents and restricted cash - net change from:
Operating, investing and financing activities	(133.5)	(72.9)	61.2
Effect of currency exchange rate changes on cash	1.0	(5.1)	(10.6)
Net change for the year	(132.5)	(78.0)	50.6
Balance at beginning of year	334.6	412.6	362.0
Balance at end of year	202.1	334.6	412.6
Cash paid for:
Interest, net of amount capitalized	15.8	15.7	18.0
Income taxes	17.3	37.3	41.6
Accrual for capital expenditures	$ 1.1	$ 6.6	$ 4.8