Basis of Accounting Presentation (Narrative) (Details) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
|
Sep. 30, 2016
USD ($)
mi
|
Sep. 30, 2015
USD ($)
|
Sep. 30, 2016
USD ($)
mi
|
Sep. 30, 2015
USD ($)
|
|
| Basis Of Accounting Presentation [Line Items] | ||||
| Pipeline Miles | mi | 15,000 | 15,000 | ||
| Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest | 15.70% | |||
| Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest Additional Ownership Interest | 46.50% | |||
| Merger related transaction costs | $ 110.4 | |||
| Employee related Merger transaction costs | 101.3 | |||
| Impairment of Long-Lived Assets to be Disposed of | $ 11.9 | $ 0.6 | $ 11.9 | $ 0.6 |
| Corporate Joint Venture [Member] | ||||
| Basis Of Accounting Presentation [Line Items] | ||||
| Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest | 84.30% | |||