Revenue From Contracts With Customers - Performance Obligations (Details) $ in Millions	Dec. 31, 2018 USD ($)
Revenue from Contract with Customer [Abstract]
Remaining performance obligation, amount	$ 187.0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligation, amount	50.1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligation, amount	36.8
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligation, amount	$ 28.1