Revenue (Contract Balances with Customer) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Abstract]
Contract asset	$ 123.0		$ 123.0		$ 117.0
Receivables from Customers	225.0		225.0		366.0
Contract with Customer, Liability	0.0		0.0		$ 0.0
Contract with Customer, Liability, Revenue Recognized	$ 0.1	$ 0.1	$ 0.3	$ 0.3