Consolidated Statements of Equity - USD ($) $ in Millions |
Total |
Limited Partners Common Units [Member]
Public [Member]
|
Limited Partners Common Units [Member]
MPC [Member]
|
Limited Partners Subordinated Units [Member]
MPC [Member]
|
General Partner [Member]
MPC [Member]
|
Noncontrolling Interest Retained by MPC [Member]
MPC [Member]
|
|---|---|---|---|---|---|---|
| Beginning Balance at Dec. 31, 2013 | $ 1,114.1 | $ 412.0 | $ 57.4 | $ 209.3 | $ (32.5) | $ 467.9 |
| Purchase of additional interest in Pipe Line Holdings | (310.0) | (172.5) | (137.5) | |||
| Net income | 141.7 | 23.8 | 20.4 | 44.2 | 3.7 | 49.6 |
| Quarterly distributions to unitholders and general partner | (75.2) | (19.6) | (16.8) | (36.4) | (2.4) | |
| Quarterly distributions to noncontrolling interest retained by MPC | (38.3) | (38.3) | ||||
| Non-cash contribution from MPC | 0.1 | 0.1 | ||||
| Equity-based compensation | 0.9 | 0.9 | ||||
| Ending Balance at Sep. 30, 2014 | 833.3 | 417.1 | 61.0 | 217.1 | (203.7) | 341.8 |
| Beginning Balance at Dec. 31, 2014 | 463.7 | 639.0 | 261.1 | 217.5 | (659.4) | 5.5 |
| Issuance of units under ATM program | 1.3 | 1.3 | ||||
| Net income | 139.1 | 34.6 | 36.2 | 48.1 | 19.4 | 0.8 |
| Quarterly distributions to unitholders and general partner | (111.6) | (28.9) | (24.7) | (45.5) | (12.5) | |
| Quarterly distributions to noncontrolling interest retained by MPC | (0.5) | (0.5) | ||||
| Subordinated unit conversion | 0.0 | 220.1 | (220.1) | |||
| Equity-based compensation | 1.1 | 1.1 | ||||
| Ending Balance at Sep. 30, 2015 | $ 493.1 | $ 647.1 | $ 492.7 | $ 0.0 | $ (652.5) | $ 5.8 |