Note 11. Employee Retirement Plans Net Retirement Expense (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Contribution Plan, Cost		$ 10.1	$ 9.1	$ 8.6
Supplemental Executive Retirement Plan (SERP) [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	[1]	$ 0.7	$ 0.7	$ 0.7

[1] The non-service cost components of net periodic benefit cost are included in other, net (income) expense in our Consolidated Statements of Operations.