Revenue Revenue - Contract Assets and Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Contract assets	$ 18.0	$ 21.8
Current Contract Assets, Percentage Change from Prior Period	(17.40%)
Contract with Customer, Asset, Net, Noncurrent	$ 0.0	0.7
Noncurrent Contract Assets, Percentage Change from Prior Period	(100.00%)
Contract with Customer, Liability, Current	$ (57.4)	(61.0)
Current Contract Liabilities, Percentage Change from Prior Period	(5.90%)
Net Contract Liabilities	$ (39.4)	$ (38.5)
Net Contract Liability, Percentage Change from Prior Period	2.30%