Investments - Equity Method Investments - Equity Method (Details) |
6 Months Ended |
|---|---|
Jun. 30, 2016 | |
| Rendezvous Gas Services, L.L.C. | |
| Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest | 78.00% |
| Three Rivers Gathering, L.L.C. | |
| Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest | 50.00% |
| Uintah Basin Field Services, L.L.C. | |
| Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest | 38.00% |