Revenue Recognition Disaggregation of Revenue (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended |
Jun. 30, 2019 | Jun. 30, 2018 | Jun. 30, 2019 | Jun. 30, 2018 |
Disaggregation of Revenue [Line Items] | | | | |
Derivative Instruments Not Designated as Hedging Instruments, Revenue | $ 40.2 | $ 33 | $ 144.3 | $ 130.8 |
Revenues | 683.4 | 840.5 | 1,518.6 | 1,955.5 |
Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenues | 199.7 | 255.5 | 382 | 595.8 |
Revenue including intersegment eliminations | 225.1 | 300.9 | 460.2 | 682.5 |
Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenues | 4.9 | 5.1 | 12.7 | 9.3 |
Revenue including intersegment eliminations | 8.1 | 7.6 | 19.5 | 13.8 |
Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenues | 478.8 | 579.9 | 1,123.9 | 1,350.4 |
Natural Gas Gathering | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 42.9 | 33.9 | 73.1 | 69.3 |
Natural Gas Gathering | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 42.9 | 33.9 | 73.1 | 69.3 |
Natural Gas Gathering | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Natural Gas Gathering | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Crude Oil Gathering | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 15.1 | 9.4 | 30.4 | 18.6 |
Crude Oil Gathering | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 15.1 | 9.4 | 30.4 | 18.6 |
Crude Oil Gathering | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Crude Oil Gathering | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Water Gathering | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 19 | 13.7 | 35.8 | 25.8 |
Water Gathering | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 19 | 13.7 | 35.8 | 25.8 |
Water Gathering | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Water Gathering | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Natural Gas Processing | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 8.1 | 2.7 | 10.6 | 5.4 |
Natural Gas Processing | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 8.1 | 2.7 | 10.6 | 5.4 |
Natural Gas Processing | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Natural Gas Processing | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
NGL Processing | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | | 2.4 | | 4.1 |
NGL Processing | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | | 0 | | 0 |
NGL Processing | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | | 0 | | 0 |
NGL Processing | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | | 2.4 | | 4.1 |
Natural Gas Compression | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 6.2 | 7.9 | 12.2 | 15.5 |
Natural Gas Compression | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 6.2 | 7.9 | 12.2 | 15.5 |
Natural Gas Compression | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Natural Gas Compression | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Crude Oil Storage | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 1.5 | 1.3 | 2.7 | 2.2 |
Crude Oil Storage | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0.5 | 0.4 | 1 | 0.9 |
Crude Oil Storage | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 1.5 | 1.2 | 2.9 | 1.8 |
Crude Oil Storage | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
NGL Storage | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 1.3 | 2.3 | 2.6 | 5.5 |
NGL Storage | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
NGL Storage | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
NGL Storage | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 1.3 | 2.3 | 2.6 | 5.5 |
Crude Oil Pipeline | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 1 | 0.9 | 2 | 1.6 |
Crude Oil Pipeline | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Crude Oil Pipeline | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 1.5 | 1.4 | 3.2 | 2.6 |
Crude Oil Pipeline | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Crude Oil Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 3.3 | 2.3 | 6.3 | 4.1 |
Crude Oil Transportation | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 1.8 | 0.6 | 3.3 | 1.2 |
Crude Oil Transportation | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Crude Oil Transportation | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 1.5 | 1.7 | 3 | 2.9 |
NGL Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 2.1 | 9.7 | 6.2 | 19.4 |
NGL Transportation | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
NGL Transportation | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
NGL Transportation | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 2.1 | 9.7 | 6.2 | 19.4 |
Water Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | | | | 0.2 |
Water Transportation | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | | | | 0 |
Water Transportation | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | | | | 0 |
Water Transportation | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | | | | 0.2 |
Crude Oil Rail Loading | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 2.5 | 3.2 | 8.3 | 6.2 |
Crude Oil Rail Loading | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Crude Oil Rail Loading | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 3.9 | 4.7 | 11.1 | 8.7 |
Crude Oil Rail Loading | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
NGL Rail Loading | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | | 1.1 | | 2.2 |
NGL Rail Loading | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | | 0 | | 0 |
NGL Rail Loading | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | | 0 | | 0 |
NGL Rail Loading | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | | 1.1 | | 2.2 |
Natural Gas Product Sales | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 14 | 18 | 48.5 | 35.3 |
Natural Gas Product Sales | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 10.9 | 11.9 | 29.7 | 25.3 |
Natural Gas Product Sales | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Natural Gas Product Sales | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 7.9 | 8.9 | 30.2 | 16.7 |
Crude Oil Product Sales | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 385.6 | 426.7 | 764 | 864.9 |
Crude Oil Product Sales | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 110.2 | 197.7 | 241.8 | 477.6 |
Crude Oil Product Sales | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Crude Oil Product Sales | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 291.4 | 266 | 581.5 | 456.6 |
NGL Product Sales | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 139.8 | 271.9 | 370.4 | 744.2 |
NGL Product Sales | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 10.4 | 22.7 | 22.3 | 42.9 |
NGL Product Sales | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
NGL Product Sales | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 133.9 | 254.8 | 355.4 | 712 |
Other revenue | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0.6 | 0.1 | 0.8 | 0.2 |
Other revenue | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Other revenue | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 1.2 | 0.3 | 2.3 | 0.7 |
Other revenue | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0.3 | 0 | 0.3 | 0 |
Intersegment Eliminations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenues | (28.6) | (47.9) | (85) | (91.2) |
Intersegment Eliminations | Natural Gas Gathering | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Intersegment Eliminations | Crude Oil Gathering | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Intersegment Eliminations | Water Gathering | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Intersegment Eliminations | Natural Gas Processing | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Intersegment Eliminations | NGL Processing | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | | 0 | | 0 |
Intersegment Eliminations | Natural Gas Compression | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Intersegment Eliminations | Crude Oil Storage | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | (0.5) | (0.3) | (1.2) | (0.5) |
Intersegment Eliminations | NGL Storage | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Intersegment Eliminations | Crude Oil Pipeline | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | (0.5) | (0.5) | (1.2) | (1) |
Intersegment Eliminations | Crude Oil Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Intersegment Eliminations | NGL Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 0 | 0 | 0 | 0 |
Intersegment Eliminations | Water Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | | | | 0 |
Intersegment Eliminations | Crude Oil Rail Loading | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | (1.4) | (1.5) | (2.8) | (2.5) |
Intersegment Eliminations | NGL Rail Loading | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | | 0 | | 0 |
Intersegment Eliminations | Natural Gas Product Sales | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | (4.8) | (2.8) | (11.4) | (6.7) |
Intersegment Eliminations | Crude Oil Product Sales | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | (16) | (37) | (59.3) | (69.3) |
Intersegment Eliminations | NGL Product Sales | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | (4.5) | (5.6) | (7.3) | (10.7) |
Intersegment Eliminations | Other revenue | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | (0.9) | (0.2) | (1.8) | (0.5) |
Revenue from Contract with Customer | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 643 | 807.5 | 1,373.9 | 1,824.7 |
Revenue from Contract with Customer | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 225.1 | 300.9 | 460.2 | 682.5 |
Revenue from Contract with Customer | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 8.1 | 7.6 | 19.5 | 13.8 |
Revenue from Contract with Customer | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | 438.4 | 546.9 | 979.2 | 1,219.6 |
Revenue from Contract with Customer | Intersegment Eliminations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Revenue from Contract with Customer, Excluding Assessed Tax | (28.6) | (47.9) | (85) | (91.2) |
Product and Service, Other | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Derivative Instruments Not Designated as Hedging Instruments, Revenue | 40.4 | | | |
Revenues | | 33 | 144.7 | 130.8 |
Product and Service, Other | Gathering and Processing Operations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Derivative Instruments Not Designated as Hedging Instruments, Revenue | 0 | | | |
Revenues | | 0 | 0 | 0 |
Product and Service, Other | Storage and Transportation | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Derivative Instruments Not Designated as Hedging Instruments, Revenue | 0 | | | |
Revenues | | 0 | 0 | 0 |
Product and Service, Other | Marketing Supply and Logistics | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Derivative Instruments Not Designated as Hedging Instruments, Revenue | 40.4 | | | |
Revenues | | 33 | 144.7 | 130.8 |
Product and Service, Other | Intersegment Eliminations | | | | |
Disaggregation of Revenue [Line Items] | | | | |
Derivative Instruments Not Designated as Hedging Instruments, Revenue | $ 0 | | | |
Revenues | | $ 0 | $ 0 | $ 0 |