CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive loss	Treasury stock	Non-controlling interest	Total
Balance at Dec. 31, 2020	$ 0.3	$ 668.3	$ 282.9	$ (219.4)	$ (49.6)	$ 324.4	$ 1,006.9
Net income			127.2			70.5	197.7
Cash dividends			(9.0)				(9.0)
Dividends paid to noncontrolling interest						(74.4)	(74.4)
Other comprehensive income (loss), net				28.1		10.1	38.2
Equity transactions with noncontrolling interest and other, net		0.7				(1.7)	(1.0)
Balance at Dec. 31, 2021	0.3	669.0	401.1	(191.3)	(49.6)	328.9	1,158.4
Net income			90.2			45.9	136.1
Cash dividends			(9.0)				(9.0)
Dividends paid to noncontrolling interest						(38.9)	(38.9)
Other comprehensive income (loss), net				47.4		16.9	64.3
Equity transactions with noncontrolling interest and other, net		0.5				(4.6)	(4.1)
Balance at Dec. 31, 2022	0.3	669.5	482.3	(143.9)	(49.6)	348.2	1,306.8
Net income			(12.1)			15.0	2.9
Cash dividends			(9.1)				(9.1)
Dividends paid to noncontrolling interest						(34.0)	(34.0)
Other comprehensive income (loss), net				(1.6)		(1.3)	(2.9)
Equity transactions with noncontrolling interest and other, net						(2.2)	(2.2)
Balance at Dec. 31, 2023	$ 0.3	$ 669.5	$ 461.1	$ (145.5)	$ (49.6)	$ 325.7	$ 1,261.5