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Note 1. Summary of Significant Accounting Policies Financial Instruments (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Concentration Risk [Line Items]
Accounts Receivable, Credit Loss Expense (Reversal)		$ 3.8
Accounts Receivable, Allowance for Credit Loss, Writeoff		0.8
Loans and Leases Receivable, Allowance		9.3
Cumulative Effect, Period of Adoption, Adjustment [Member]
Concentration Risk [Line Items]
Cumulative effect of adopting new accounting standards		0.5	$ 13.7
Cumulative Effect, Period of Adoption, Adjustment [Member] \| Retained Earnings [Member]
Concentration Risk [Line Items]
Cumulative effect of adopting new accounting standards	$ 0.7	$ 0.5	$ 13.7	$ 18.7