Revenue Recognition Net Contract Assets (Liabilities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Contract with Customer, Liability, Revenue Recognized	$ 7.2	$ 3.3	$ 4.8
Contract with Customer, Liability, Current	5.5	8.4
Contract with Customer, Liability, Current, Net, Change in Timeframe, Performance Obligation Satisfied Revenue Recognized	$ 2.9
Contract with Customer, Liability, Current, Net, Change in Timeframe, Performance Obligation Satisfied Revenue Recognized, Percent	(35.20%)
Contract with Customer, Liability, Noncurrent	$ 5.6	5.9
Contract with Customer, Liability, Noncurrent, Net, Change in Timeframe, Performance Obligation Satisfied Revenue Recognized	$ 0.3
Contract with Customer, Liability, Noncurrent, Net, Change in Timeframe, Performance Obligation Satisfied Revenue Recognized, Percent	(5.10%)
Contract with Customer, Asset (Liability), Net	$ (11.1)	$ (14.3)
Contract with Customer, Asset (Liability), Change in Timeframe, Performance Obligation Satisfied Revenue Recognized	$ 3.2