Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred tax liability adjustment due to tax act	$ 5.6	$ 6.7	$ 8.6
Increase (decrease) in unrecognized tax benefits	(1.4)
Unrecognized tax benefits that would impact effective tax rate	6.2	7.2
Interest and penalty expense, excluding refunds	0.2	(0.1)	$ 0.5
Accrued interest and penalty	$ 3.1	$ 2.8