Revenue from Contracts with Customers (Narrative) (Details) $ in Millions	Dec. 31, 2018 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Future Revenue Amounts Related to Remaining Performance Obligations	$ 123.5
Remaining Performance Obligation, Expected Timing of Satisfaction	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Future Revenue Amounts Related to Remaining Performance Obligations	$ 149.4
Remaining Performance Obligation, Expected Timing of Satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Future Revenue Amounts Related to Remaining Performance Obligations	$ 128.5
Remaining Performance Obligation, Expected Timing of Satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Future Revenue Amounts Related to Remaining Performance Obligations	$ 113.6
Remaining Performance Obligation, Expected Timing of Satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Future Revenue Amounts Related to Remaining Performance Obligations	$ 82.7
Remaining Performance Obligation, Expected Timing of Satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Future Revenue Amounts Related to Remaining Performance Obligations	$ 370.7
Remaining Performance Obligation, Expected Timing of Satisfaction