Other Commitments And Contingencies (Estimated Aggregate Amounts Of Minimum Fixed Payments On Purchase And Service Obligations) (Details) - Pipeline Service Agreements [Member] $ in Millions |
Dec. 31, 2015
USD ($)
|
|---|---|
| Other Commitments And Contingencies [Line Items] | |
| 2016 | $ 51.5 |
| 2017 | 49.5 |
| 2018 | 42.0 |
| 2019 | 25.4 |
| 2020 | 24.2 |
| After | 66.8 |
| Total future minimum payments | $ 259.4 |