Revenue Recognition (Net Contract Assets (Liabilities)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Revenue Recognition and Deferred Revenue [Abstract]
Contract with Customer, Liability, Revenue Recognized	$ 1.1	$ 1.6
Contract with Customer, Asset, Net	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	$ (5.4)		(13.0)
Contract with Customer, Liability, Current, Net, Change in Timeframe, Performance Obligation Satisfied Revenue Recognized	$ 7.6
Contract with Customer, Liability, Current, Net, Change in Timeframe, Performance Obligation Satisfied Revenue Recognized, Percent	(58.50%)
Contract with Customer, Liability, Noncurrent	$ (5.7)		(5.9)
Contract with Customer, Liability, Noncurrent, Net, Change in Timeframe, Performance Obligation Satisfied Revenue Recognized	$ 0.2
Contract with Customer, Liability, Noncurrent, Net, Change in Timeframe, Performance Obligation Satisfied Revenue Recognized, Percent	(3.40%)
Contract with Customer, Asset (Liability), Net	$ (11.1)		$ (16.4)
Contract with Customer, Asset (Liability), Change in Timeframe, Performance Obligation Satisfied Revenue Recognized	$ 5.3