Revenue Recognition (Net Contract Assets (Liabilities)) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Revenue Recognition and Deferred Revenue [Abstract]
Contract with Customer, Liability, Revenue Recognized	$ 1.5	$ 1.3	$ 2.6	$ 2.9
Contract with Customer, Asset, Net	0.0		0.0		$ 2.5
Contract with Customer, Asset, Cumulative Catch-up Adjustment to Revenue, Change in Measure of Progress			$ (2.5)
Contract with Customer, Asset, Cumulative Catch-up Adjustment to Revenue, Change in Measure of Progress, Percent			(100.00%)
Contract with Customer, Liability, Current	(4.9)		$ (4.9)		(13.0)
Contract with Customer, Liability, Current, Net, Change in Timeframe, Performance Obligation Satisfied Revenue Recognized			$ 8.1
Contract with Customer, Liability, Current, Net, Change in Timeframe, Performance Obligation Satisfied Revenue Recognized, Percent			(62.20%)
Contract with Customer, Liability, Noncurrent	(6.0)		$ (6.0)		(5.9)
Contract with Customer, Liability, Noncurrent, Net, Change in Timeframe, Performance Obligation Satisfied Revenue Recognized			$ (0.1)
Contract with Customer, Liability, Noncurrent, Net, Change in Timeframe, Performance Obligation Satisfied Revenue Recognized, Percent			1.70%
Contract with Customer, Asset (Liability), Net	$ (10.9)		$ (10.9)		$ (16.4)
Contract with Customer, Asset (Liability), Change in Timeframe, Performance Obligation Satisfied Revenue Recognized			$ 5.5