Revenue Revenue (Details Textuals) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)
Revenue from Contract with Customer [Abstract]
Percentage of revenue mix recognizable over time	90.00%	90.00%
Revenue recognized from deferred revenue during the period	$ 67.7	$ 210.3
Unsatisfied performance obligations	$ 2,500.0	$ 2,500.0
Percent of remaining performance obligations, current	60.00%	60.00%
Revenue recognized from satisfaction of performance obligations	$ 8.3	$ 14.5
Capitalized contract costs, net	23.2	23.2
Amortization of capitalized contract costs	$ 5.9	$ 11.0