Revenue from Contract with Customer Revenue from Contract with Customer (Textuals) (Details) - USD ($) $ in Millions		3 Months Ended
	Jan. 01, 2018	Mar. 31, 2017	Mar. 31, 2018	Dec. 31, 2017
Revenue from Contract with Customer [Abstract]
Contract with Customer, Asset, Credit Loss Expense	$ 8.8	$ 9.8
Deferred Revenue, Revenue Recognized	$ 121.9
Deferred revenue			$ 502.0	$ 437.5
Revenue, Remaining Performance Obligation			$ 2,200.0