Equity - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Schedule of accumulated other comprehensive loss
Balance at the beginning of the period	$ (68.9)
Current-year change	(17.4)
Balance at the end of the period	(86.3)
Deferred tax assets in accumulated other comprehensive loss, pension liabilities	1.3	$ 3.3
Income tax portion attributable to settlement of Reliance SERP	0.3
Foreign Currency Translation Loss
Schedule of accumulated other comprehensive loss
Balance at the beginning of the period	(55.2)
Current-year change	(28.8)
Balance at the end of the period	(84.0)
Pension and Postretirement Benefit Plan Adjustments, Net of Tax
Schedule of accumulated other comprehensive loss
Balance at the beginning of the period	(13.7)
Current-year change	11.4
Balance at the end of the period	$ (2.3)