Income Taxes Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Reduction In General And Administrative Expense Due To Uncertain Tax Positions Realized	$ 2.5
Uncertain Tax Position Benefit Recognized	(19.0)
Interest Related to Uncertain Tax Positions	4.1	$ (0.7)	$ (0.7)
Balance as of January 1,	19.0	19.0
Balance as of December 31,	$ 0.0	$ 19.0	$ 19.0