Debt (Tables)

6 Months Ended

Jun. 30, 2020

Debt Disclosure [Abstract]

Outstanding Borrowings

Our outstanding borrowings at June 30, 2020 and December 31, 2019 consisted of the following:

(In millions)	June 30, 2020			December 31, 2019
Marathon Petroleum Corporation:
Senior notes	$	10,974		$	8,474
Notes payable	10			10
Finance lease obligations	683			679
MPLX LP:
Bank revolving credit facility	825			—
Term loan facility	1,000			1,000
Senior notes	19,100			19,100
Finance lease obligations	13			19
Total debt	$	32,605		$	29,282
Unamortized debt issuance costs	(143		)	(134		)
Unamortized (discount) premium, net	(296		)	(310		)
Amounts due within one year	(1,715		)	(711		)
Total long-term debt due after one year	$	30,451		$	28,127

Schedule of Line of Credit Facilities [Table Text Block]

Available Capacity under our Facilities as of June 30, 2020

(Dollars in millions)	Total Capacity		Outstanding Borrowings		Outstanding Letters of Credit		Available Capacity		Weighted Average Interest Rate		Expiration
MPC, excluding MPLX
MPC 364-day bank revolving credit facility	$	1,000	$	—	$	—	$	1,000	—		September 2020
MPC 364-day bank revolving credit facility	1,000		—		—		1,000		—		April 2021
MPC bank revolving credit facility(a)	5,000		—		1		4,999		—		October 2023
MPC trade receivables securitization facility(b)	705		—		—		705		—		July 2021
MPLX
MPLX bank revolving credit facility(c)	3,500		825		—		2,675		1.36	%	July 2024

^(a)  Borrowed $3.5 billion and repaid $3.5 billion during the six months ended June 30, 2020.

^(b)  Borrowed $1.175 billion and repaid $1.175 billion during the six months ended June 30, 2020. Availability under our $750 million trade receivables facility is a function of eligible trade receivables, which will be lower in a sustained lower price environment for refined products.

^(c) 

Borrowed $2.5 billion at an average interest rate of 1.53 percent and repaid $1.675 billion during the six months ended June 30, 2020.