Debt - Outstanding Borrowings (Detail) - USD ($)
$ in Millions |
3 Months Ended |
|
|
Mar. 31, 2018 |
Feb. 08, 2018 |
Dec. 31, 2017 |
| Debt Instrument [Line Items] |
|
|
|
|
| Commercial paper |
|
$ 0
|
|
|
| Total |
|
17,807
|
|
$ 13,418
|
| Unamortized debt issuance costs |
|
(109)
|
|
(59)
|
| Unamortized discount |
[1] |
(440)
|
|
(413)
|
| Amounts due within one year |
|
(26)
|
|
(624)
|
| Total long-term debt due after one year |
|
17,232
|
|
12,322
|
| MPLX LP |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Amounts due within one year |
|
(1)
|
|
(1)
|
| Total long-term debt due after one year |
|
11,861
|
|
6,945
|
| Senior Notes | MPLX LP |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
|
$ 5,500
|
|
| Senior Notes | MarkWest | MPLX LP |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Unamortized discount |
|
(362)
|
|
(374)
|
| Trade receivables securitization facility due July 2019 |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
0
|
|
|
| MPLX bank revolving credit facility due 2022 | Line of Credit | MPLX LP |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
0
|
|
|
| MPLX senior notes, 3.375%, due March 2023 | Senior Notes | MPLX LP |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
|
$ 500
|
|
| Debt instrument, interest rate |
|
|
3.375%
|
|
| MPLX senior notes, 4.000%, due March 2028 | Senior Notes | MPLX LP |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
|
$ 1,250
|
|
| Debt instrument, interest rate |
|
|
4.00%
|
|
| MPLX senior notes, 4.500%, due April 2038 | Senior Notes | MPLX LP |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
|
$ 1,750
|
|
| Debt instrument, interest rate |
|
|
4.50%
|
|
| MPLX senior notes, 4.700%, due April 2048 | Senior Notes | MPLX LP |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
|
$ 1,500
|
|
| Debt instrument, interest rate |
|
|
4.70%
|
|
| MPLX senior notes, 4.900%, due April 2058 | Senior Notes | MPLX LP |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
|
$ 500
|
|
| Debt instrument, interest rate |
|
|
4.90%
|
|
| Marathon Petroleum Corporation |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Commercial paper |
|
0
|
|
0
|
| Marathon Petroleum Corporation | Capital Lease Obligations |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Capital lease obligations |
|
$ 350
|
|
356
|
| Debt instrument maturity year, start |
|
Jan. 01, 2018
|
|
|
| Debt instrument maturity year, end |
|
Mar. 31, 2033
|
|
|
| Marathon Petroleum Corporation | 364-day bank revolving credit facility due July 2018 | Line of Credit |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 0
|
|
0
|
| Line of credit facility, expiration date |
|
Jul. 20, 2018
|
|
|
| Marathon Petroleum Corporation | Trade receivables securitization facility due July 2019 | Secured Debt |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 0
|
|
0
|
| Line of credit facility, expiration date |
|
Jul. 19, 2019
|
|
|
| Marathon Petroleum Corporation | Bank revolving credit facility due 2022 | Line of Credit |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 0
|
|
0
|
| Line of credit facility, expiration date |
|
Jul. 21, 2022
|
|
|
| Marathon Petroleum Corporation | Senior notes, 2.700% due December 2018 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 0
|
|
600
|
| Debt instrument, maturity date |
|
Dec. 14, 2018
|
|
|
| Debt instrument, interest rate |
|
2.70%
|
|
|
| Marathon Petroleum Corporation | Senior notes, 3.400% due December 2020 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 650
|
|
650
|
| Debt instrument, maturity date |
|
Dec. 15, 2020
|
|
|
| Debt instrument, interest rate |
|
3.40%
|
|
|
| Marathon Petroleum Corporation | Senior notes, 5.125% due March 2021 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 1,000
|
|
1,000
|
| Debt instrument, maturity date |
|
Mar. 01, 2021
|
|
|
| Debt instrument, interest rate |
|
5.125%
|
|
|
| Marathon Petroleum Corporation | Senior notes, 3.625%, due September 2024 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 750
|
|
750
|
| Debt instrument, maturity date |
|
Sep. 15, 2024
|
|
|
| Debt instrument, interest rate |
|
3.625%
|
|
|
| Marathon Petroleum Corporation | Senior notes, 6.500%, due March 2041 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 1,250
|
|
1,250
|
| Debt instrument, maturity date |
|
Mar. 01, 2041
|
|
|
| Debt instrument, interest rate |
|
6.50%
|
|
|
| Marathon Petroleum Corporation | Senior notes, 4.750%, due September 2044 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 800
|
|
800
|
| Debt instrument, maturity date |
|
Sep. 15, 2044
|
|
|
| Debt instrument, interest rate |
|
4.75%
|
|
|
| Marathon Petroleum Corporation | Senior notes, 5.850% due December 2045 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 250
|
|
250
|
| Debt instrument, maturity date |
|
Dec. 15, 2045
|
|
|
| Debt instrument, interest rate |
|
5.85%
|
|
|
| Marathon Petroleum Corporation | Senior notes, 5.000%, due September 2054 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 400
|
|
400
|
| Debt instrument, maturity date |
|
Sep. 15, 2054
|
|
|
| Debt instrument, interest rate |
|
5.00%
|
|
|
| MPLX LP | Senior Notes | MarkWest |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 63
|
|
63
|
| MPLX LP | Capital Lease Obligations |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Capital lease obligations |
|
$ 7
|
|
7
|
| Debt instrument maturity year, start |
|
Jan. 01, 2018
|
|
|
| Debt instrument maturity year, end |
|
Mar. 31, 2020
|
|
|
| MPLX LP | MPLX 364-day term loan | Unsecured Debt |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 0
|
|
0
|
| Line of credit facility, expiration date |
|
Dec. 31, 2018
|
|
|
| MPLX LP | MPLX term loan facility due 2019 | Unsecured Debt |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 0
|
|
0
|
| Line of credit facility, expiration date |
|
Nov. 20, 2019
|
|
|
| MPLX LP | MPLX bank revolving credit facility due 2022 | Line of Credit |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 0
|
|
505
|
| Line of credit facility, expiration date |
|
Jul. 21, 2022
|
|
|
| MPLX LP | MPLX senior notes, 5.500%, due February 2023 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 710
|
|
710
|
| Debt instrument, maturity date |
|
Feb. 15, 2023
|
|
|
| Debt instrument, interest rate |
|
5.50%
|
|
|
| MPLX LP | MPLX senior notes, 5.500%, due February 2023 | Senior Notes | MarkWest |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Debt instrument, maturity date |
|
Feb. 15, 2023
|
|
|
| Debt instrument, interest rate |
|
5.50%
|
|
|
| MPLX LP | MPLX senior notes, 3.375%, due March 2023 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 500
|
|
0
|
| Debt instrument, maturity date |
|
Mar. 15, 2023
|
|
|
| Debt instrument, interest rate |
|
3.375%
|
|
|
| MPLX LP | MPLX senior notes, 4.500%, due July 2023 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 989
|
|
989
|
| Debt instrument, maturity date |
|
Jul. 15, 2023
|
|
|
| Debt instrument, interest rate |
|
4.50%
|
|
|
| MPLX LP | MPLX senior notes, 4.500%, due July 2023 | Senior Notes | MarkWest |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Debt instrument, maturity date |
|
Jul. 15, 2023
|
|
|
| Debt instrument, interest rate |
|
4.50%
|
|
|
| MPLX LP | MPLX senior notes, 4.875%, due December 2024 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 1,149
|
|
1,149
|
| Debt instrument, maturity date |
|
Dec. 01, 2024
|
|
|
| Debt instrument, interest rate |
|
4.875%
|
|
|
| MPLX LP | MPLX senior notes, 4.875%, due December 2024 | Senior Notes | MarkWest |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Debt instrument, maturity date |
|
Dec. 01, 2024
|
|
|
| Debt instrument, interest rate |
|
4.875%
|
|
|
| MPLX LP | MPLX senior notes, 4.000%, due February 2025 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 500
|
|
500
|
| Debt instrument, maturity date |
|
Feb. 15, 2025
|
|
|
| Debt instrument, interest rate |
|
4.00%
|
|
|
| MPLX LP | MPLX senior notes, 4.875%, due June 2025 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 1,189
|
|
1,189
|
| Debt instrument, maturity date |
|
Jun. 01, 2025
|
|
|
| Debt instrument, interest rate |
|
4.875%
|
|
|
| MPLX LP | MPLX senior notes, 4.875%, due June 2025 | Senior Notes | MarkWest |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Debt instrument, maturity date |
|
Jun. 01, 2025
|
|
|
| Debt instrument, interest rate |
|
4.875%
|
|
|
| MPLX LP | MPLX senior notes, 4.125%, due March 2027 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 1,250
|
|
1,250
|
| Debt instrument, maturity date |
|
Mar. 01, 2027
|
|
|
| Debt instrument, interest rate |
|
4.125%
|
|
|
| MPLX LP | MPLX senior notes, 4.000%, due March 2028 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 1,250
|
|
0
|
| Debt instrument, maturity date |
|
Mar. 15, 2028
|
|
|
| Debt instrument, interest rate |
|
4.00%
|
|
|
| MPLX LP | MPLX senior notes, 4.500%, due April 2038 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 1,750
|
|
0
|
| Debt instrument, maturity date |
|
Apr. 15, 2038
|
|
|
| Debt instrument, interest rate |
|
4.50%
|
|
|
| MPLX LP | MPLX senior notes, 5.200%, due March 2047 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 1,000
|
|
1,000
|
| Debt instrument, maturity date |
|
Mar. 01, 2047
|
|
|
| Debt instrument, interest rate |
|
5.20%
|
|
|
| MPLX LP | MPLX senior notes, 4.700%, due April 2048 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 1,500
|
|
0
|
| Debt instrument, maturity date |
|
Apr. 15, 2048
|
|
|
| Debt instrument, interest rate |
|
4.70%
|
|
|
| MPLX LP | MPLX senior notes, 4.900%, due April 2058 | Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Long-term debt, gross |
|
$ 500
|
|
$ 0
|
| Debt instrument, maturity date |
|
Apr. 15, 2058
|
|
|
| Debt instrument, interest rate |
|
4.90%
|
|
|
|
|