MPLX LP - Noncontrolling Interest in MPLX (Details) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
|
| Increase in MPC's additional paid-in capital, net of tax | $ (546) | $ 114 |
| Additional Paid-in Capital | ||
| Increase due to the issuance of MPLX LP common units to the public | 4 | 10 |
| Increase due to the issuance of MPLX LP common units and general partner units to MPC | 1,114 | 96 |
| Increase due to GP/IDR Exchange | 1,808 | 0 |
| Increase in MPC's additional paid-in capital | 2,926 | 106 |
| Tax impact | (546) | (34) |
| Increase in MPC's additional paid-in capital, net of tax | $ 2,380 | $ 72 |