Revenue from Contracts with Customers (Revenue Performance Obligation Narrative) (Details) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01 $ in Millions	Sep. 30, 2019 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 1,021.0
Revenue, Remaining Performance Obligation, Expected Timing Of Satisfaction, Percentage	90.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	24 months