Allowance for Credit Losses (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Receivables [Abstract]
Credit loss expense (reversal) and available-for-sale, allowance for credit loss	$ 2.0	$ (30.0)
Net (charge-offs) recoveries	$ 3.2	0.9
Time period used for projecting future conditions to estimate credit losses	2 years
Financing receivable, allowance for credit loss, period increase (decrease)	$ (2.1)
Other financial assets, allowance for credit loss	$ 1.1	$ 1.7	$ 1.0	$ 0.8