Income Taxes (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]
Reduction to alternative minimum tax credit, percent		6.60%
Deferred tax liability adjustment due to tax act		$ 6.7	$ 8.6
Increase (decrease) in unrecognized tax benefits		(4.6)
Tax settlement paid	$ 4.6
Unrecognized tax benefits that would impact effective tax rate		7.2	11.5
Interest and penalty expense, excluding refunds		(0.1)	0.5	$ (1.1)
Accrued interest and penalty		$ 2.8	$ 2.9