Marathon Petroleum (MPC) 10-Q 1 Aug 23 2023 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2023	Jul. 26, 2023
Cover [Abstract]
Entity Central Index Key	0001510295
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus (Q1,Q2,Q3,FY)	Q2
Amendment Flag	false
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2023
Document Transition Report	false
Entity File Number	001-35054
Entity Registrant Name	Marathon Petroleum Corporation
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	27-1284632
Entity Address, Address Line One	539 South Main Street
Entity Address, City or Town	Findlay
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	45840-3229
City Area Code	419
Local Phone Number	422-2121
Title of 12(b) Security	Common Stock, par value $.01
Trading Symbol	MPC
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		399,844,048

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023		Jun. 30, 2022
Revenues and other income:
Sales and other operating revenues	$ 36,343	$ 53,795	$ 71,207	[1]	$ 91,853	[1]
Income from equity method investments	199	147	332		289
Net gain on disposal of assets	13	39	16		21
Other income	269	257	346		459
Total revenues and other income	36,824	54,238	71,901		92,622
Costs and expenses:
Cost of revenues (excludes items below)	31,762	44,207	61,056		79,275
Depreciation and amortization	834	819	1,634		1,624
Selling, general and administrative expenses	704	694	1,395		1,297
Other taxes	219	190	450		382
Total costs and expenses	33,519	45,910	64,535		82,578
Income from operations	3,305	8,328	7,366		10,044
Net interest and other financial costs	142	312	296		574
Income before income taxes	3,163	8,016	7,070		9,470
Provision for income taxes	583	1,799	1,406		2,081
Net income	2,580	6,217	5,664		7,389
Less net income attributable to:
Redeemable noncontrolling interest	23	21	46		42
Noncontrolling interests	331	323	668		629
Net income attributable to MPC	$ 2,226	$ 5,873	$ 4,950		$ 6,718
Basic:
Net income attributable to MPC per share	$ 5.34	$ 11.03	$ 11.49		$ 12.24
Weighted average shares outstanding	417	532	430		549
Diluted:
Net income attributable to MPC per share	$ 5.32	$ 10.95	$ 11.44		$ 12.15
Weighted average shares outstanding	419	536	432		553
[1]Includes related party sales. See Note 6 for additional information

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Net income	$ 2,580	$ 6,217	$ 5,664	$ 7,389
Other comprehensive income (loss)	(21)	9	(32)	2
Comprehensive income	2,559	6,226	5,632	7,391
Less comprehensive income attributable to:
Redeemable noncontrolling interest	23	21	46	42
Noncontrolling interests	331	323	668	629
Comprehensive income attributable to MPC	2,205	5,882	4,918	6,720
Actuarial changes
Other comprehensive income (loss)	(6)	21	(4)	33
Prior service
Other comprehensive income (loss)	(12)	(12)	(25)	(25)
Other
Other comprehensive income (loss)	$ (3)	$ 0	$ (3)	$ (6)

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Actuarial changes
OCI, tax expense (benefit)	$ (2)	$ 7	$ (1)	$ 11
Prior service
OCI, tax expense (benefit)	(4)	(4)	(8)	(8)
Other
OCI, tax expense (benefit)	$ (1)	$ 0	$ (1)	$ (2)

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Assets
Cash and cash equivalents	$ 7,345	$ 8,625
Short-term investments	4,109	3,145
Receivables, less allowance for doubtful accounts of $54 and $29, respectively	10,274	13,477
Inventories	9,536	8,827
Other current assets	949	1,168
Total current assets	32,213	35,242
Equity method investments	6,665	6,466
Property, plant and equipment, net	35,059	35,657
Goodwill	8,244	8,244
Right of use assets	1,288	1,214
Other noncurrent assets	2,973	3,081
Total assets	86,442	89,904
Liabilities
Accounts payable	13,052	15,312
Payroll and benefits payable	712	967
Accrued taxes	1,160	1,140
Debt due within one year	72	1,066
Operating lease liabilities	423	368
Other current liabilities	2,047	1,167
Total current liabilities	17,466	20,020
Long-term debt	27,211	25,634
Deferred income taxes	5,913	5,904
Defined benefit postretirement plan obligations	1,181	1,114
Long-term operating lease liabilities	859	841
Deferred credits and other liabilities	1,244	1,304
Total liabilities	53,874	54,817
Commitments and contingencies (see Note 23)
Redeemable noncontrolling interest	968	968
Equity
Preferred stock, no shares issued and outstanding (par value $0.00 per share, 30 million shares authorized)	0	0
Common stock:
Issued – 992 million and 990 million shares (par value $0.01 per share, 2 billion shares authorized)	10	10
Held in treasury, at cost – 587 million and 536 million shares	(38,119)	(31,841)
Additional paid-in capital	33,411	33,402
Retained earnings	30,442	26,142
Accumulated other comprehensive income (loss)	(30)	2
Total MPC stockholders’ equity	25,714	27,715
Noncontrolling interests	5,886	6,404
Total equity	31,600	34,119
Total liabilities, redeemable noncontrolling interest and equity	$ 86,442	$ 89,904

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Millions, $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Accounts receivable, allowance for credit loss, current	$ 54	$ 29
Preferred stock:
Preferred stock, shares issued	0
Preferred stock, shares outstanding	0
Preferred stock, par or stated value per share	$ 0
Preferred stock, shares authorized	30
Common stock:
Common Stock, Shares, Issued	992	990
Common stock, par or stated value per share	$ 0.01
Common stock, shares authorized	2,000
Treasury stock, shares	(587)	(536)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023		Jun. 30, 2022
Operating activities:
Net income	$ 5,664		$ 7,389
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of deferred financing costs and debt discount	(27)		33
Depreciation and amortization	1,634		1,624
Pension and other postretirement benefits, net	25		117
Deferred income taxes	22		(92)
Net gain on disposal of assets	(16)		(21)
Income from equity method investments	(332)		(289)
Distributions from equity method investments	429		336
Changes in income tax receivable	46		11
Changes in the fair value of derivative instruments	88		(169)
Changes in:
Current receivables	3,238		(6,282)
Inventories	(708)		(2,979)
Current accounts payable and accrued liabilities	(1,861)		10,106
Right of use assets and operating lease liabilities, net	(1)		2
All other, net	(160)		(277)
Cash provided by operating activities - continuing operations	8,041		9,509
Cash used in operating activities - discontinued operations	0		(44)
Net cash provided by operating activities	8,041		9,465
Investing activities:
Additions to property, plant and equipment	(938)		(993)
Acquisitions, net of cash acquired	0		(74)
Disposal of assets	24		72
Investments – acquisitions and contributions	(296)		(160)
Investments - redemptions, repayments and return of capital	0		0
Purchases of short-term investments	(4,723)		(2,581)
Sales of short-term investments	1,583		1,075
Maturities of short-term investments	2,231		2,811
All other, net	423		470
Net cash provided by (used in) investing activities	(1,696)		620
Financing activities:
Long-term debt – borrowings	1,589		2,385
Long-term debt – repayments	(1,043)		(1,237)
Debt issuance costs	(15)		(16)
Issuance of common stock	27		167
Common stock repurchased	(6,248)		(6,177)
Dividends paid	(653)		(643)
Distributions to noncontrolling interests	(635)		(599)
Repurchases of noncontrolling interests	0		(135)
Redemption of noncontrolling interests - preferred units	(600)		0
All other, net	(49)		(41)
Net cash used in financing activities	(7,627)		(6,296)
Net change in cash, cash equivalents and restricted cash	(1,282)		3,789
Cash, cash equivalents, restricted cash and restricted cash equivalents, beginning balance	8,631	[1]	5,294
Cash, cash equivalents, restricted cash and restricted cash equivalents, ending balance	$ 7,349	[1]	$ 9,083
[1]Restricted cash is included in other current assets on our consolidated balance sheets.

Consolidated Statements of Equi

Consolidated Statements of Equity and Redeemable Noncontrolling Interest (Consolidated Statements of Equity) - USD ($) $ in Millions	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Non-controlling Interests
Beginning balance at Dec. 31, 2021	$ 32,616	$ 10	$ (19,904)	$ 33,262	$ 12,905	$ (67)	$ 6,410
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,151				845		306
Dividends declared on common stock	(330)				(330)
Distributions to noncontrolling interests	(290)						(290)
Other comprehensive income (loss)	(7)					(7)
Shares repurchased	(2,807)		(2,807)
Shares returned - stock based compensation			0
Shares issued - stock based compensation				90
Net shares issued - stock based compensation	89						(1)
Equity transactions of MPLX	(88)			(25)			(63)
Ending balance at Mar. 31, 2022	30,334	10	(22,711)	33,327	13,420	(74)	6,362
Beginning balance at Dec. 31, 2021	32,616	10	(19,904)	33,262	12,905	(67)	6,410
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss)	2
Equity transactions of MPLX				(45)
Ending balance at Jun. 30, 2022	32,704	10	(26,000)	33,378	18,983	(65)	6,398
Beginning balance at Mar. 31, 2022	30,334	10	(22,711)	33,327	13,420	(74)	6,362
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	6,196				5,873		323
Dividends declared on common stock	(310)				(310)
Distributions to noncontrolling interests	(267)						(267)
Other comprehensive income (loss)	9					9
Shares repurchased	(3,285)		(3,285)
Shares returned - stock based compensation			(4)
Shares issued - stock based compensation				71
Net shares issued - stock based compensation	69						2
Equity transactions of MPLX	(42)			(20)			(22)
Ending balance at Jun. 30, 2022	32,704	10	(26,000)	33,378	18,983	(65)	6,398
Beginning balance at Dec. 31, 2022	34,119	10	(31,841)	33,402	26,142	2	6,404
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,061				2,724		337
Dividends declared on common stock	(336)				(336)
Distributions to noncontrolling interests	(306)						(306)
Other comprehensive income (loss)	(11)					(11)
Shares repurchased	(3,238)		(3,238)
Shares returned - stock based compensation			0
Shares issued - stock based compensation				3
Net shares issued - stock based compensation	3						0
Equity transactions of MPLX	(597)			3	(2)		(598)
Ending balance at Mar. 31, 2023	32,695	10	(35,079)	33,408	28,528	(9)	5,837
Beginning balance at Dec. 31, 2022	34,119	10	(31,841)	33,402	26,142	2	6,404
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss)	(32)
Equity transactions of MPLX				3
Ending balance at Jun. 30, 2023	31,600	10	(38,119)	33,411	30,442	(30)	5,886
Beginning balance at Mar. 31, 2023	32,695	10	(35,079)	33,408	28,528	(9)	5,837
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,557				2,226		331
Dividends declared on common stock	(312)				(312)
Distributions to noncontrolling interests	(283)						(283)
Other comprehensive income (loss)	(21)					(21)
Shares repurchased	(3,040)		(3,040)
Shares returned - stock based compensation			0
Shares issued - stock based compensation				3
Net shares issued - stock based compensation	4						1
Equity transactions of MPLX	0			0			0
Ending balance at Jun. 30, 2023	$ 31,600	$ 10	$ (38,119)	$ 33,411	$ 30,442	$ (30)	$ 5,886

Consolidated Statements of Eq_2

Consolidated Statements of Equity and Redeemable Noncontrolling Interest (Shares of Common Stock) - shares shares in Millions	Total	Common Stock
Beginning balance at Dec. 31, 2021		984
Number of common shares issued - stock compensation		3
Ending balance at Mar. 31, 2022		987
Number of common shares issued - stock compensation		2
Ending balance at Jun. 30, 2022		989
Beginning balance at Dec. 31, 2022	990	990
Number of common shares issued - stock compensation		1
Ending balance at Mar. 31, 2023		991
Number of common shares issued - stock compensation		1
Ending balance at Jun. 30, 2023	992	992

Consolidated Statements of Eq_3

Consolidated Statements of Equity and Redeemable Noncontrolling Interest (Shares of Treasury Stock) - shares shares in Millions	Total	Treasury Stock
Beginning balance at Dec. 31, 2021		(405)
Number of shares repurchased		(37)
Number of shares returned - stock compensation		0
Ending balance at Mar. 31, 2022		(442)
Beginning balance at Dec. 31, 2021		(405)
Number of shares repurchased	(71)
Ending balance at Jun. 30, 2022		(476)
Beginning balance at Mar. 31, 2022		(442)
Number of shares repurchased	(34)	(34)
Number of shares returned - stock compensation		0
Ending balance at Jun. 30, 2022		(476)
Beginning balance at Dec. 31, 2022	(536)	(536)
Number of shares repurchased		(25)
Number of shares returned - stock compensation		0
Ending balance at Mar. 31, 2023		(561)
Beginning balance at Dec. 31, 2022	(536)	(536)
Number of shares repurchased	(51)
Ending balance at Jun. 30, 2023	(587)	(587)
Beginning balance at Mar. 31, 2023		(561)
Number of shares repurchased	(26)	(26)
Number of shares returned - stock compensation		0
Ending balance at Jun. 30, 2023	(587)	(587)

Consolidated Statements of Eq_4

Consolidated Statements of Equity and Redeemable Noncontrolling Interest (Redeemable Noncontrolling Interest) - USD ($) $ in Millions	Total	Redeemable Non-controlling Interest
Beginning balance at Dec. 31, 2021		$ 965
Net income attributable to redeemable noncontrolling interest		21
Distributions to noncontrolling interests		(21)
Ending balance at Mar. 31, 2022		965
Beginning balance at Dec. 31, 2021		965
Net income attributable to redeemable noncontrolling interest	$ 42
Ending balance at Jun. 30, 2022		965
Beginning balance at Mar. 31, 2022		965
Net income attributable to redeemable noncontrolling interest	21	21
Distributions to noncontrolling interests		(21)
Ending balance at Jun. 30, 2022		965
Beginning balance at Dec. 31, 2022	968	968
Net income attributable to redeemable noncontrolling interest		23
Distributions to noncontrolling interests		(23)
Ending balance at Mar. 31, 2023		968
Beginning balance at Dec. 31, 2022	968	968
Net income attributable to redeemable noncontrolling interest	46
Ending balance at Jun. 30, 2023	968	968
Beginning balance at Mar. 31, 2023		968
Net income attributable to redeemable noncontrolling interest	23	23
Distributions to noncontrolling interests		(23)
Ending balance at Jun. 30, 2023	$ 968	$ 968

Consolidated Statements of Eq_5

Consolidated Statements of Equity and Redeemable Noncontrolling Interest (Parenthetical) - $ / shares	3 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022
Statement of Stockholders' Equity [Abstract]
Dividends declared per share of common stock (in dollars per share)	$ 0.75	$ 0.75	$ 0.58	$ 0.58

Description of the Business and

Description of the Business and Basis of Presentation	6 Months Ended
	Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of the Business and Basis of Presentation	Description of the Business and Basis of Presentation Description of the Business We are a leading, integrated, downstream energy company headquartered in Findlay, Ohio. We operate the nation's largest refining system. We sell refined products to wholesale marketing customers domestically and internationally, to buyers on the spot market and to independent entrepreneurs who operate branded outlets. We also sell transportation fuel to consumers through direct dealer locations under long-term supply contracts. MPC’s midstream operations are primarily conducted through MPLX LP (“MPLX”), which owns and operates crude oil and light product transportation and logistics infrastructure as well as gathering, processing and fractionation assets. We own the general partner and a majority limited partner interest in MPLX. See Note 4. Basis of Presentation All significant intercompany transactions and accounts have been eliminated. These interim consolidated financial statements are unaudited; however, in the opinion of our management, these statements reflect all adjustments necessary for a fair statement of the results for the periods reported. All such adjustments are of a normal, recurring nature unless otherwise disclosed. These interim consolidated financial statements, including the notes, have been prepared in accordance with the rules of the SEC applicable to interim period financial statements and do not include all of the information and disclosures required by GAAP for complete financial statements. Certain information and disclosures derived from our audited annual financial statements, prepared in accordance with GAAP, have been condensed or omitted from these interim financial statements. These interim consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2022. The results of operations for the three and six months ended June 30, 2023 are not necessarily indicative of the results to be expected for the full year.

Accounting Standards

Accounting Standards	6 Months Ended
	Jun. 30, 2023
Accounting Standards Update and Change in Accounting Principle [Abstract]
Accounting Standards	Accounting Standards Not Yet Adopted ASU 2023-01, Leases (Topic 842): Common Control Arrangements In March 2023, the FASB issued an ASU to amend certain provisions of ASC 842 that apply to arrangements between related parties under common control. The ASU amends the accounting for the amortization period of leasehold improvements in common-control leases for all entities and requires certain disclosures when the lease term is shorter than the useful life of the asset. This ASU is effective for fiscal years beginning after December 15, 2023, including interim periods within those fiscal years. Early adoption is permitted. We do not expect the application of this ASU to have a material impact on our consolidated financial statements or financial disclosures.

Short-term Investments

Short-term Investments	6 Months Ended
	Jun. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Short-term Investments	Short-Term Investments Investments Components The components of investments were as follows: June 30, 2023 (Millions of dollars) Fair Value Level Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash and Cash Equivalents Short-term Investments Available-for-sale debt securities Commercial paper Level 2 $ 2,088 $ — $ (1) $ 2,087 $ 447 $ 1,640 Certificates of deposit and time deposits Level 2 3,340 — (1) 3,339 2,562 777 U.S. government securities Level 1 1,965 — (4) 1,961 309 1,652 Corporate notes and bonds Level 2 40 — — 40 — 40 Total available-for-sale debt securities $ 7,433 $ — $ (6) $ 7,427 $ 3,318 $ 4,109 Cash 4,027 4,027 — Total $ 11,454 $ 7,345 $ 4,109 December 31, 2022 (Millions of dollars) Fair Value Level Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash and Cash Equivalents Short-term Investments Available-for-sale debt securities Commercial paper Level 2 $ 3,074 $ — $ (1) $ 3,073 $ 1,106 $ 1,967 Certificates of deposit and time deposits Level 2 2,093 — — 2,093 1,500 593 U.S. government securities Level 1 1,071 — — 1,071 498 573 Corporate notes and bonds Level 2 66 — — 66 54 12 Total available-for-sale debt securities $ 6,304 $ — $ (1) $ 6,303 $ 3,158 $ 3,145 Cash 5,467 5,467 — Total $ 11,770 $ 8,625 $ 3,145 Our investment policy includes concentration limits and credit rating requirements which limits our investments to high quality, short term and highly liquid securities. Realized gains/losses were not material. All of our available-for-sale debt securities held as of June 30, 2023 mature within one year or less or are readily available for use.

Master Limited Partnership

Master Limited Partnership	6 Months Ended
	Jun. 30, 2023
Noncontrolling Interest [Abstract]
Master Limited Partnership	Master Limited Partnership We own the general partner and a majority limited partner interest in MPLX, which owns and operates crude oil and light product transportation and logistics infrastructure as well as gathering, processing and fractionation assets. We control MPLX through our ownership of the general partner interest and, as of June 30, 2023, we owned approximately 65 percent of the outstanding MPLX common units. Unit Repurchase Program In November 2020, MPLX announced the board authorization of a unit repurchase program for the repurchase of up to $1.0 billion of MPLX’s outstanding common units held by the public, which was utilized in 2022. On August 2, 2022 , MPLX announced its board of directors approved a $1.0 billion unit repurchase authorization. The u nit repurchase authorizations have no expiration date. MPLX may utilize various methods to effect the repurchases, which could include open market repurchases, negotiated block transactions, accelerated unit repurchases, tender offers or open market solicitations for units, some of which may be effected through Rule 10b5-1 plans. The timing and amount of future repurchases, if any, will depend upon several factors, including market and business conditions, and such repurchases may be discontinued at any time. Total unit repurchases were as follows for the respective periods: Three Months Ended Six Months Ended (In millions, except per share data) 2023 2022 2023 2022 Number of common units repurchased — 1 — 4 Cash paid for common units repurchased $ — $ 35 $ — $ 135 Average cost per unit $ — $ 33.74 $ — $ 32.48 As of June 30, 2023, MPLX had approximately $846 million remaining under its unit repurchase authorization. Redemption of the Series B Preferred Units On February 15, 2023, MPLX exercised its right to redeem all of its 600,000 outstanding preferred units (the “Series B preferred units”). MPLX paid unitholders the Series B preferred unit redemption price of $1,000 per unit. The final semi-annual distribution on the Series B preferred units was paid on February 15, 2023 in the usual manner. The excess of the total redemption price of $600 million paid to Series B preferred unitholders over the carrying value of the Series B preferred units on the redemption date resulted in a $2 million net reduction to retained earnings. The Series B preferred units were included in noncontrolling interest on our consolidated balance sheet at December 31, 2022. Agreements We have various long-term, fee-based commercial agreements with MPLX. Under these agreements, MPLX provides transportation, storage, distribution and marketing services to us. With certain exceptions, these agreements generally contain minimum volume commitments. These transactions are eliminated in consolidation but are reflected as intersegment transactions between our Refining & Marketing and Midstream segments. We also have agreements with MPLX that establish fees for operational and management services provided between us and MPLX and for executive management services and certain general and administrative services provided by us to MPLX. These transactions are eliminated in consolidation but are reflected as intersegment transactions between corporate and our Midstream segment. Noncontrolling Interest As a result of equity transactions of MPLX, we are required to adjust non-controlling interest and additional paid-in capital. Changes in MPC’s additional paid-in capital resulting from changes in its ownership interests in MPLX were as follows: Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Increase (decrease) due to change in ownership $ — $ (13) $ 1 $ (50) Tax impact — (7) 2 5 Increase (decrease) in MPC's additional paid-in capital, net of tax $ — $ (20) $ 3 $ (45)

Variable Interest Entities

Variable Interest Entities	6 Months Ended
	Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	Variable Interest Entities Consolidated VIE We control MPLX through our ownership of its general partner. MPLX is a VIE because the limited partners do not have substantive kick-out or participating rights over the general partner. We are the primary beneficiary of MPLX because in addition to our significant economic interest, we also have the ability, through our ownership of the general partner, to control the decisions that most significantly impact MPLX. We therefore consolidate MPLX and record a noncontrolling interest for the interest owned by the public. We also record a redeemable noncontrolling interest related to MPLX’s Series A preferred units. The creditors of MPLX do not have recourse to MPC’s general credit through guarantees or other financial arrangements, except as noted. MPC has effectively guaranteed certain indebtedness of LOOP LLC (“LOOP”) and LOCAP LLC (“LOCAP”), in which MPLX holds an interest. See Note 23 for more information. The assets of MPLX can only be used to settle its own obligations and its creditors have no recourse to our assets, except as noted earlier. The following table presents balance sheet information for the assets and liabilities of MPLX, which are included in our consolidated balance sheets. (Millions of dollars) June 30, December 31, Assets Cash and cash equivalents $ 755 $ 238 Receivables, less allowance for doubtful accounts 728 747 Inventories 146 148 Other current assets 52 56 Equity method investments 4,124 4,095 Property, plant and equipment, net 18,692 18,848 Goodwill 7,645 7,645 Right of use assets 281 283 Other noncurrent assets 1,611 1,664 Liabilities Accounts payable $ 588 $ 664 Payroll and benefits payable — 4 Accrued taxes 82 67 Debt due within one year 1 988 Operating lease liabilities 49 46 Other current liabilities 331 338 Long-term debt 20,405 18,808 Deferred income taxes 13 13 Long-term operating lease liabilities 228 230 Deferred credits and other liabilities 385 366

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2023
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Transactions with related parties were as follows: Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Sales to related parties $ 263 $ 21 $ 452 $ 40 Purchases from related parties 480 297 791 579 Sales to related parties, which are included in sales and other operating revenues, consist primarily of refined product sales and renewable feedstock sales to certain of our equity affiliates.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2023
Earnings Per Share [Abstract]
Earnings (Loss) per Share	Earnings Per Share We compute basic earnings per share by dividing net income attributable to MPC less income allocated to participating securities by the weighted average number of shares of common stock outstanding. Since MPC grants certain incentive compensation awards to employees and non-employee directors that are considered to be participating securities, we have calculated our earnings per share using the two-class method. Diluted income per share assumes exercise of certain share-based compensation awards, provided the effect is not anti-dilutive. Three Months Ended Six Months Ended (In millions, except per share data) 2023 2022 2023 2022 Net income $ 2,580 $ 6,217 $ 5,664 $ 7,389 Net income attributable to noncontrolling interest (354) (344) (714) (671) Net income allocated to participating securities (1) (3) (3) (3) Redemption of preferred units — — (2) — Income available to common stockholders $ 2,225 $ 5,870 $ 4,945 $ 6,715 Weighted average common shares outstanding: Basic 417 532 430 549 Effect of dilutive securities 2 4 2 4 Diluted 419 536 432 553 Income available to common stockholders per share: Basic: Net income attributable to MPC per share $ 5.34 $ 11.03 $ 11.49 $ 12.24 Diluted: Net income attributable to MPC per share $ 5.32 $ 10.95 $ 11.44 $ 12.15 The following table summarizes the shares that were anti-dilutive and, therefore, were excluded from the diluted share calculation. Three Months Ended Six Months Ended (In millions) 2023 2022 2023 2022 Shares issuable under share-based compensation plans — — — —

Equity

Equity	6 Months Ended
	Jun. 30, 2023
Equity [Abstract]
Equity	Equity In May 2021, MPC announced the authorization of a share repurchase program of up to $7.1 billion. Subsequently, in February 2022, MPC announced a $5.0 billion share repurchase authorization. Both these authorizations were utilized in 2022. In August 2022, MPC announced a $5.0 billion share repurchase authorization and announced additional $5.0 billion share repurchase authorizations in both January 2023 and in May 2023. As of June 30, 2023, $7.12 billion remained available for repurchase under these authorizations. These authorizations have no expiration date. We may utilize various methods to effect the repurchases, which could include open market repurchases, negotiated block transactions, tender offers, accelerated share repurchases or open market solicitations for shares, some of which may be effected through Rule 10b5-1 plans. The timing and amount of future repurchases, if any, will depend upon several factors, including market and business conditions, and such repurchases may be suspended or discontinued at any time. Total share repurchases were as follows for the respective periods: Three Months Ended Six Months Ended (In millions, except per share data) 2023 2022 2023 2022 Number of shares repurchased 26 34 51 71 Cash paid for shares repurchased $ 3,068 $ 3,331 $ 6,248 $ 6,177 Average cost per share (a) $ 117.62 $ 95.46 $ 122.07 $ 85.31 (a) The average cost per share for the 2023 period includes a 1% excise tax on share repurchases resulting from the Inflation Reduction Act of 2022 . The number of shares repurchased shown above and the amount remaining available under the share repurchase authorizations reflect the repurchase of 540,000 common shares for $63 million that were transacted in the second quarter of 2023 and settled in the third quarter of 2023.

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2023
Segment Reporting [Abstract]
Segment Information	Segment Information We have two reportable segments: Refining & Marketing and Midstream. Each of these segments is organized and managed based upon the nature of the products and services it offers. • Refining & Marketing – refines crude oil and other feedstocks, including renewable feedstocks, at our refineries in the Gulf Coast, Mid-Continent and West Coast regions of the United States, purchases refined products and ethanol for resale and distributes refined products, including renewable diesel, through transportation, storage, distribution and marketing services provided largely by our Midstream segment. We sell refined products to wholesale marketing customers domestically and internationally, to buyers on the spot market, to independent entrepreneurs who operate primarily Marathon ® branded outlets and through long-term fuel supply contracts with direct dealers who operate locations mainly under the ARCO ® brand. • Midstream – gathers, transports, stores and distributes crude oil, refined products, including renewable diesel, and other hydrocarbon-based products principally for the Refining & Marketing segment via refining logistics assets, pipelines, terminals, towboats and barges; gathers, processes and transports natural gas; and transports, fractionates, stores and markets NGLs. The Midstream segment primarily reflects the results of MPLX. Our chief operating decision maker (“CODM”) evaluates the performance of our segments using segment adjusted EBITDA. Our CODM is the chief executive officer. Amounts included in income before income taxes and excluded from segment adjusted EBITDA include: (i) depreciation and amortization; (ii) net interest and other financial costs; (iii) turnaround expenses and (iv) other adjustments as deemed necessary. These items are either: (i) believed to be non-recurring in nature; (ii) not believed to be allocable or controlled by the segment; or (iii) not tied to the operational performance of the segment. Assets by segment are not a measure used to assess the performance of the company by the CODM and thus are not reported in our disclosures. Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Segment adjusted EBITDA for reportable segments Refining & Marketing $ 3,163 $ 7,760 $ 7,016 $ 9,134 Midstream 1,532 1,456 3,062 2,859 Total reportable segments $ 4,695 $ 9,216 $ 10,078 $ 11,993 Reconciliation of segment adjusted EBITDA for reportable segments to income before income taxes Total reportable segments $ 4,695 $ 9,216 $ 10,078 $ 11,993 Corporate (164) (156) (329) (294) Refining planned turnaround costs (392) (151) (749) (296) Renewable volume obligation requirements — 238 — 238 Litigation — — — 27 Depreciation and amortization (834) (819) (1,634) (1,624) Net interest and other financial costs (142) (312) (296) (574) Income before income taxes $ 3,163 $ 8,016 $ 7,070 $ 9,470 Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Sales and other operating revenues Refining & Marketing Revenues from external customers (a) $ 35,167 $ 52,300 $ 68,830 $ 89,092 Intersegment revenues 21 47 48 83 Refining & Marketing segment revenues 35,188 52,347 68,878 89,175 Midstream Revenues from external customers (a) 1,176 1,495 2,377 2,761 Intersegment revenues 1,347 1,308 2,709 2,555 Midstream segment revenues 2,523 2,803 5,086 5,316 Total segment revenues 37,711 55,150 73,964 94,491 Less: intersegment revenues 1,368 1,355 2,757 2,638 Consolidated sales and other operating revenues (a) $ 36,343 $ 53,795 $ 71,207 $ 91,853 (a) Includes related party sales. See Note 6 for additional information. Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Income (loss) from equity method investments Refining & Marketing $ 17 $ 6 $ (19) $ 18 Midstream 182 141 351 271 Corporate — — — — Consolidated income from equity method investments $ 199 $ 147 $ 332 $ 289 Depreciation and amortization Refining & Marketing $ 484 $ 475 $ 948 $ 936 Midstream 331 330 648 661 Corporate 19 14 38 27 Consolidated depreciation and amortization $ 834 $ 819 $ 1,634 $ 1,624 Capital expenditures Refining & Marketing $ 243 $ 315 $ 664 $ 559 Midstream 273 222 514 505 Segment capital expenditures and investments 516 537 1,178 1,064 Less investments in equity method investees 89 48 296 160 Plus: Corporate 33 15 40 38 Capitalized interest 13 25 34 48 Consolidated capital expenditures (a) $ 473 $ 529 $ 956 $ 990 (a) Includes changes in capital expenditure accruals. See Note 19 for a reconciliation of total capital expenditures to additions to property, plant and equipment for the six months ended June 30, 2023 and 2022 as reported in the consolidated statements of cash flows.

Net Interest and Other Financia

Net Interest and Other Financial Costs	6 Months Ended
	Jun. 30, 2023
Other Income and Expenses [Abstract]
Net Interest and Other Financial Costs	Net Interest and Other Financial Costs Net interest and other financial costs were as follows: Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Interest income $ (119) $ (18) $ (240) $ (23) Interest expense 329 324 663 634 Interest capitalized (13) (25) (36) (48) Pension and other postretirement non-service costs (a) (25) 32 (48) 11 Loss on extinguishment of debt — — 9 — Investments - net premium (discount) amortization (31) (5) (59) (6) Other financial costs 1 4 7 6 Net interest and other financial costs $ 142 $ 312 $ 296 $ 574 (a) See Note 22.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes We recorded a combined federal, state and foreign income tax provision of $583 million and $1.41 billion for the three and six months ended June 30, 2023, respectively, which was lower than the U.S. statutory rate primarily due to net income attributable to noncontrolling interests, a benefit related to foreign derived intangible income, offset by state taxes. We recorded a combined federal, state and foreign income tax provision of $1.80 billion and $2.08 billion for the three and six months ended June 30, 2022, respectively, which was higher than the U.S. statutory rate primarily due to state taxes offset by net income attributable to noncontrolling interests.

Inventories

Inventories	6 Months Ended
	Jun. 30, 2023
Inventory Disclosure [Abstract]
Inventories	Inventories (Millions of dollars) June 30, December 31, Crude oil $ 3,279 $ 3,047 Refined products 5,254 4,748 Materials and supplies 1,003 1,032 Total $ 9,536 $ 8,827

Equity Method Investments

Equity Method Investments	6 Months Ended
	Jun. 30, 2023
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Equity Method Investments LF Bioenergy Acquisition On March 8, 2023, MPC announced the acquisition of a 49.9 percent interest in LF Bioenergy, an emerging producer of renewable natural gas (“RNG”) in the U.S., for approximately $56 million, which included funding for on-going operations and project development. LF Bioenergy has been focused on developing and growing a portfolio of dairy farm-based, low carbon intensity RNG projects. LF Bioenergy is a VIE since it is unable to fund its operations without financial support from its equity owners. We are not the primary beneficiary of this VIE because we do not have the ability to control the activities that significantly influence the economic outcomes of the entity and, therefore, do not consolidate the entity. MPC accounts for our ownership interest in LF Bioenergy as an equity method investment. Watson Cogeneration Company On June 1, 2022, MPC purchased the remaining 49 percent interest in Watson Cogeneration Company from NRG Energy, Inc. for approximately $59 million. This entity is now consolidated and included in our consolidated results. It was previously accounted for as an equity method investment.

Property, Plant and Equipment (

Property, Plant and Equipment (PP&E)	6 Months Ended
	Jun. 30, 2023
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment (PP&E) June 30, 2023 December 31, 2022 (Millions of dollars) Gross Accumulated Depreciation Net Gross Accumulated Depreciation Net Refining & Marketing $ 32,712 $ 17,576 $ 15,136 $ 32,292 $ 16,745 $ 15,547 Midstream 28,043 8,689 19,354 27,659 8,118 19,541 Corporate 1,589 1,020 569 1,550 981 569 Total $ 62,344 $ 27,285 $ 35,059 $ 61,501 $ 25,844 $ 35,657

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair Values—Recurring The following tables present assets and liabilities accounted for at fair value on a recurring basis as of June 30, 2023 and December 31, 2022 by fair value hierarchy level. We have elected to offset the fair value amounts recognized for multiple derivative contracts executed with the same counterparty, including any related cash collateral as shown below; however, fair value amounts by hierarchy level are presented on a gross basis in the following tables. June 30, 2023 Fair Value Hierarchy (Millions of dollars) Level 1 Level 2 Level 3 Netting and Collateral (a) Net Carrying Value on Balance Sheet (b) Collateral Pledged Not Offset Assets: Commodity contracts $ 338 $ 10 $ — $ (330) $ 18 $ 53 Liabilities: Commodity contracts $ 361 $ — $ — $ (361) $ — $ — Embedded derivatives in commodity contracts — — 53 — 53 — December 31, 2022 Fair Value Hierarchy (Millions of dollars) Level 1 Level 2 Level 3 Netting and Collateral (a) Net Carrying Value on Balance Sheet (b) Collateral Pledged Not Offset Assets: Commodity contracts $ 310 $ — $ — $ (243) $ 67 $ 100 Liabilities: Commodity contracts $ 301 $ — $ — $ (301) $ — $ — Embedded derivatives in commodity contracts — — 61 — 61 — (a) Represents the impact of netting assets, liabilities and cash collateral when a legal right of offset exists. As of June 30, 2023, cash collateral of $31 million was netted with mark-to-market derivative liabilities. As of December 31, 2022, cash collateral of $58 million was netted with mark-to-market derivative liabilities. (b) We have no derivative contracts which are subject to master netting arrangements reflected gross on the balance sheet. Level 2 instruments include over-the-counter fixed swaps to mitigate the price risk from MPLX’s sales of propane. The swap valuations are based on observable inputs in the form of forward prices based on Mont Belvieu propane forward spot prices and contain no significant unobservable inputs. Level 3 instruments relate to an embedded derivative liability for a natural gas purchase commitment embedded in a keep‑whole processing agreement. The fair value calculation for these Level 3 instruments at June 30, 2023 used significant unobservable inputs including: (1) NGL prices interpolated and extrapolated due to inactive markets ranging from $0.54 to $1.34 per gallon with a weighted average of $0.72 per gallon and (2) the probability of renewal of 100 percent for the five The following is a reconciliation of the beginning and ending balances recorded for net liabilities classified as Level 3 in the fair value hierarchy. Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Beginning balance $ 58 $ 99 $ 61 $ 108 Unrealized and realized gain included in net income (3) (4) (3) (8) Settlements of derivative instruments (2) (3) (5) (8) Ending balance $ 53 $ 92 $ 53 $ 92 The amount of total gain for the period included in earnings attributable to the change in unrealized losses relating to liabilities still held at the end of period: $ (3) $ (3) $ (3) $ (8) Fair Values – Reported We believe the carrying value of our other financial instruments, including cash and cash equivalents, receivables, accounts payable and certain accrued liabilities, approximate fair value. Our fair value assessment incorporates a variety of considerations, including the short-term duration of the instruments and the expected insignificance of bad debt expense, which includes an evaluation of counterparty credit risk. The borrowings under our revolving credit facilities, which include variable interest rates, approximate fair value. The fair value of our long-term debt is based on prices from recent trade activity and is categorized in level 3 of the fair value hierarchy. The carrying and fair values of our debt were approximately $26.9 billion and $24.5 billion at June 30, 2023, respectively, and approximately $26.3 billion and $24.0 billion at December 31, 2022, respectively. These carrying and fair values of our debt exclude the unamortized issuance costs which are netted against our total debt.

Derivatives

Derivatives	6 Months Ended
	Jun. 30, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	Derivatives For further information regarding the fair value measurement of derivative instruments, including any effect of master netting agreements or collateral, see Note 15. We do not designate any of our commodity derivative instruments as hedges for accounting purposes. Derivatives that are not designated as accounting hedges may include commodity derivatives used to hedge price risk on (1) inventories, (2) fixed price sales of refined products, (3) the acquisition of foreign-sourced crude oil, (4) the acquisition of ethanol for blending with refined products, (5) the sale of NGLs, (6) the purchase of natural gas, (7) the purchase of soybean oil and (8) the sale of propane. The following table presents the fair value of derivative instruments as of June 30, 2023 and December 31, 2022 and the line items in the consolidated balance sheets in which the fair values are reflected. The fair value amounts below are presented on a gross basis and do not reflect the netting of asset and liability positions permitted under the terms of our master netting arrangements including cash collateral on deposit with, or received from, brokers. We offset the recognized fair value amounts for multiple derivative instruments executed with the same counterparty in our financial statements when a legal right of offset exists. As a result, the asset and liability amounts below will not agree with the amounts presented in our consolidated balance sheets. (Millions of dollars) June 30, 2023 December 31, 2022 Balance Sheet Location Asset Liability Asset Liability Commodity derivatives Other current assets $ 348 $ 361 $ 310 $ 301 Other current liabilities (a) — 7 — 10 Deferred credits and other liabilities (a) — 46 — 51 (a) Includes embedded derivatives. The table below summarizes open commodity derivative contracts for crude oil, refined products, blending products, soybean oil and propane as of June 30, 2023. Percentage of contracts that expire next quarter Position (Units in thousands of barrels) Long Short Exchange-traded (a) Crude oil 53.1% 74,081 79,120 Refined products 86.9% 15,695 14,661 Blending products 49.6% 1,958 4,433 Soybean oil 76.6% 4,610 5,150 Over-the-counter Propane 50.5% — 809 (a) Included in exchange-traded are spread contracts in thousands of barrels: Crude oil - 20,150 long and 20,500 short; Refined products - 2,449 long and 995 short. There are no spread contracts for blending products or soybean oil. The following table summarizes the effect of all commodity derivative instruments in our consolidated statements of income: Gain (Loss) (Millions of dollars) Three Months Ended Six Months Ended Income Statement Location 2023 2022 2023 2022 Sales and other operating revenues $ 8 $ — $ 10 $ — Cost of revenues 50 17 111 (325) Other income — (1) 1 1 Total $ 58 $ 16 $ 122 $ (324)

Debt

Debt	6 Months Ended
	Jun. 30, 2023
Debt Disclosure [Abstract]
Debt	Debt Our outstanding borrowings at June 30, 2023 and December 31, 2022 consisted of the following: (Millions of dollars) June 30, December 31, Marathon Petroleum Corporation: Senior notes $ 6,449 $ 6,449 Notes payable 1 1 Finance lease obligations 493 522 Total 6,943 6,972 MPLX LP: Senior notes 20,700 20,100 Finance lease obligations 7 8 Total 20,707 20,108 Total debt 27,650 27,080 Unamortized debt issuance costs (150) (142) Unamortized discount, net of unamortized premium (217) (238) Amounts due within one year (72) (1,066) Total long-term debt due after one year $ 27,211 $ 25,634 MPLX Senior Notes On February 9, 2023, MPLX issued $1.6 billion aggregate principal amount of senior notes in a public offering, consisting of $1.1 billion aggregate principal amount of 5.00 percent senior notes due March 2033 and $500 million aggregate principal amount of 5.65 percent senior notes due March 2053. On February 15, 2023, MPLX used $600 million of the net proceeds to redeem all of its outstanding Series B preferred units. On March 13, 2023, MPLX used the remaining proceeds to redeem all of MPLX’s and MarkWest’s $1.0 billion aggregate principal amount of 4.50 percent senior notes due July 2023. The redemption resulted in a loss on extinguishment of debt of $9 million due to the immediate expense recognition of unamortized debt discount and issuance costs. Available Capacity under our Credit Facilities as of June 30, 2023 (Millions of dollars) Total Outstanding Outstanding Available Weighted Expiration MPC, excluding MPLX MPC bank revolving credit facility $ 5,000 $ — $ 1 $ 4,999 — % July 2027 MPC trade receivables securitization facility (a) 100 — 100 — — September 2023 MPLX MPLX bank revolving credit facility 2,000 — — 2,000 — % July 2027 (a) The committed borrowing and letter of credit issuance capacity of the trade receivables securitization facility is $100 million. In addition, the facility allows for the issuance of letters of credit in excess of the committed capacity at the discretion of the issuing banks. As of June 30, 2023, letters of credit in the total amount of $386 million were issued and outstanding under the facility to secure contracts awarded by the Department of Energy to purchase crude oil from the Strategic Petroleum Reserve.

Revenue

Revenue	6 Months Ended
	Jun. 30, 2023
Revenue from Contract with Customer [Abstract]
Revenue	Revenue The following table presents our revenues from external customers disaggregated by segment and product line. Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Refining & Marketing Refined products $ 32,864 $ 48,864 $ 64,787 $ 82,457 Crude oil 1,875 2,976 3,205 5,865 Services and other 428 460 838 770 Total revenues from external customers 35,167 52,300 68,830 89,092 Midstream Refined products 377 698 797 1,195 Services and other 799 797 1,580 1,566 Total revenues from external customers 1,176 1,495 2,377 2,761 Sales and other operating revenues $ 36,343 $ 53,795 $ 71,207 $ 91,853 We do not disclose information on the future performance obligations for any contract with expected duration of one year or less at inception. As of June 30, 2023, we do not have future performance obligations that are material to future periods. Receivables On the accompanying consolidated balance sheets, receivables, less allowance for doubtful accounts primarily consists of customer receivables. Significant, non-customer balances included in our receivables at June 30, 2023 include matching buy/sell receivables of $4.55 billion.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	6 Months Ended
	Jun. 30, 2023
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information Six Months Ended (Millions of dollars) 2023 2022 Net cash provided by operating activities included: Interest paid (net of amounts capitalized) $ 584 $ 519 Net income taxes paid to (received from) taxing authorities 1,400 1,123 Non-cash investing and financing activities: Book value of equity method investment (a) — 25 (a) Represents the book value of MPC’s equity method investment in Watson Cogeneration Company at June 1, 2022. See Note 13 for additional information. The consolidated statements of cash flows exclude changes to the consolidated balance sheets that did not affect cash. The following is a reconciliation of additions to property, plant and equipment to total capital expenditures: Six Months Ended (Millions of dollars) 2023 2022 Additions to property, plant and equipment per the consolidated statements of cash flows $ 938 $ 993 Increase (decrease) in capital accruals 18 (3) Total capital expenditures $ 956 $ 990

Other Current Liabilities

Other Current Liabilities	6 Months Ended
	Jun. 30, 2023
Other Liabilities Disclosure [Abstract]
Other Liabilities Disclosure	Other Current Liabilities The following summarizes the components of other current liabilities: (Millions of dollars) June 30, December 31, Environmental credits liability $ 1,135 $ 429 Accrued interest payable 325 315 Other current liabilities 587 423 Total other current liabilities $ 2,047 $ 1,167

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	6 Months Ended
	Jun. 30, 2023
Equity [Abstract]
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Income (Loss) The following table shows the changes in accumulated other comprehensive income (loss) by component. Amounts in parentheses indicate debits. (Millions of dollars) Pension Benefits Other Benefits Other Total Balance as of December 31, 2021 $ (117) $ 49 $ 1 $ (67) Other comprehensive gain (loss) before reclassifications, net of tax of $(8) (19) 3 (6) (22) Amounts reclassified from accumulated other comprehensive loss: Amortization of prior service credit (a) (23) (11) — (34) Amortization of actuarial loss (a) 7 3 — 10 Settlement loss (a) 56 — — 56 Tax effect (10) 2 — (8) Other comprehensive income (loss) 11 (3) (6) 2 Balance as of June 30, 2022 $ (106) $ 46 $ (5) $ (65) (Millions of dollars) Pension Benefits Other Benefits Other Total Balance as of December 31, 2022 $ (163) $ 165 $ — $ 2 Other comprehensive gain (loss) before reclassifications, net of tax of $0 (4) 3 (3) (4) Amounts reclassified from accumulated other comprehensive loss: Amortization of prior service credit (a) (22) (11) — (33) Amortization of actuarial gain (a) (3) — — (3) Settlement loss (a) (2) — — (2) Tax effect 7 3 — 10 Other comprehensive loss (24) (5) (3) (32) Balance as of June 30, 2023 $ (187) $ 160 $ (3) $ (30) (a) These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. See Note 22.

Pension and Other Postretiremen

Pension and Other Postretirement Benefits	6 Months Ended
	Jun. 30, 2023
Retirement Benefits [Abstract]
Pension and Other Postretirement Plans	Pension and Other Postretirement Benefits The following summarizes the components of net periodic benefit costs: Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Pension Benefits Service cost $ 48 $ 65 $ 97 $ 133 Interest cost 29 24 58 47 Expected return on plan assets (42) (37) (84) (78) Amortization of prior service credit (11) (12) (22) (23) Amortization of actuarial (gain) loss (1) 3 (3) 7 Settlement loss (2) 54 (2) 56 Net periodic pension benefit cost $ 21 $ 97 $ 44 $ 142 Other Benefits Service cost $ 5 $ 5 $ 10 $ 13 Interest cost 8 5 16 10 Amortization of prior service credit (6) (6) (11) (11) Amortization of actuarial loss — 1 — 3 Net periodic other benefit cost $ 7 $ 5 $ 15 $ 15 The components of net periodic benefit cost other than the service cost component are included in net interest and other financial costs on the consolidated statements of income. During the six months ended June 30, 2023, we made no contributions to our funded pension plans. Benefit payments related to unfunded pension and other postretirement benefit plans were $7 million and $27 million, respectively, during the six months ended June 30, 2023.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies We are the subject of, or a party to, a number of pending or threatened legal actions, contingencies and commitments involving a variety of matters, including laws and regulations relating to the environment. Some of these matters are discussed below. For matters for which we have not recorded a liability, we are unable to estimate a range of possible loss because the issues involved have not been fully developed through pleadings, discovery or court proceedings. However, the ultimate resolution of some of these contingencies could, individually or in the aggregate, be material. Environmental Matters We are subject to federal, state, local and foreign laws and regulations relating to the environment. These laws generally provide for control of pollutants released into the environment and require responsible parties to undertake remediation of hazardous waste disposal sites and certain other locations including presently or formerly owned or operated retail marketing sites. Penalties may be imposed for noncompliance. At June 30, 2023 and December 31, 2022, accrued liabilities for remediation totaled $374 million and $387 million, respectively. It is not presently possible to estimate the ultimate amount of all remediation costs that might be incurred or the penalties, if any, that may be imposed. Receivables for recoverable costs from certain states, under programs to assist companies in clean-up efforts related to underground storage tanks at presently or formerly owned or operated retail marketing sites, were $5 million at both June 30, 2023 and December 31, 2022. Governmental and other entities in various states have filed climate-related lawsuits against numerous energy companies, including MPC. The lawsuits allege damages as a result of climate change and the plaintiffs are seeking unspecified damages and abatement under various tort theories. We are currently subject to such proceedings in federal or state courts in California, Delaware, Maryland, Hawaii, Rhode Island, South Carolina and Oregon. Similar lawsuits may be filed in other jurisdictions. At this early stage, the ultimate outcome of these matters remains uncertain, and neither the likelihood of an unfavorable outcome nor the ultimate liability, if any, can be determined. We are involved in a number of environmental enforcement matters arising in the ordinary course of business. While the outcome and impact on us cannot be predicted with certainty, management believes the resolution of these environmental matters will not, individually or collectively, have a material adverse effect on our consolidated results of operations, financial position or cash flows. Other Legal Proceedings In July 2020, Tesoro High Plains Pipeline Company, LLC (“THPP”), a subsidiary of MPLX, received a Notification of Trespass Determination from the Bureau of Indian Affairs (“BIA”) relating to a portion of the Tesoro High Plains Pipeline that crosses the Fort Berthold Reservation in North Dakota. The notification demanded the immediate cessation of pipeline operations and assessed trespass damages of approximately $187 million. After subsequent appeal proceedings and in compliance with a new order issued by the BIA, in December 2020, THPP paid approximately $4 million in assessed trespass damages and ceased use of the portion of the pipeline that crosses the property at issue. In March 2021, the BIA issued an order purporting to vacate the BIA’s prior orders related to THPP’s alleged trespass and direct the Regional Director of the BIA to reconsider the issue of THPP’s alleged trespass and issue a new order. In April 2021, THPP filed a lawsuit in the District of North Dakota against the United States of America, the U.S. Department of the Interior and the BIA (together, the “U.S. Government Parties”) challenging the March 2021 order purporting to vacate all previous orders related to THPP’s alleged trespass. On February 8, 2022, the U.S. Government Parties filed their answer and counterclaims to THPP’s suit claiming THPP is in continued trespass with respect to the pipeline and seek disgorgement of pipeline profits from June 1, 2013 to present, removal of the pipeline and remediation. We intend to vigorously defend ourselves against these counterclaims. We are also a party to a number of other lawsuits and other proceedings arising in the ordinary course of business. While the ultimate outcome and impact to us cannot be predicted with certainty, we believe that the resolution of these other lawsuits and proceedings will not, individually or collectively, have a material adverse effect on our consolidated financial position, results of operations or cash flows. Guarantees We have provided certain guarantees, direct and indirect, of the indebtedness of other companies. Under the terms of most of these guarantee arrangements, we would be required to perform should the guaranteed party fail to fulfill its obligations under the specified arrangements. In addition to these financial guarantees, we also have various performance guarantees related to specific agreements. Guarantees related to indebtedness of equity method investees LOOP and LOCAP MPC and MPLX hold interests in an offshore oil port, LOOP, and MPLX holds an interest in a crude oil pipeline system, LOCAP. Both LOOP and LOCAP have secured various project financings with throughput and deficiency agreements. Under the agreements, MPC, as a shipper, is required to advance funds if the investees are unable to service their debt. Any such advances are considered prepayments of future transportation charges. The duration of the agreements varies but tend to follow the terms of the underlying debt, which extend through 2037. Our maximum potential undiscounted payments under these agreements for the debt principal totaled $171 million as of June 30, 2023. Dakota Access Pipeline MPLX holds a 9.19 percent indirect interest in a joint venture (“Dakota Access”) that owns and operates the Dakota Access Pipeline and Energy Transfer Crude Oil Pipeline projects, collectively referred to as the Bakken Pipeline system or DAPL. In 2020, the U.S. District Court for the District of Columbia (the “D.D.C.”) ordered the U.S. Army Corps of Engineers (“Army Corps”), which granted permits and an easement for the Bakken Pipeline system, to prepare an environmental impact statement (“EIS”) relating to an easement under Lake Oahe in North Dakota. The D.D.C. later vacated the easement. The Army Corps expects to release a draft EIS in 2023. In May 2021, the D.D.C. denied a renewed request for an injunction to shut down the pipeline while the EIS is being prepared. In June 2021, the D.D.C. issued an order dismissing without prejudice the tribes’ claims against the Dakota Access Pipeline. The litigation could be reopened or new litigation challenging the EIS, once completed, could be filed. The pipeline remains operational. MPLX has entered into a Contingent Equity Contribution Agreement whereby it, along with the other joint venture owners in the Bakken Pipeline system, has agreed to make equity contributions to the joint venture upon certain events occurring to allow the entities that own and operate the Bakken Pipeline system to satisfy their senior note payment obligations. The senior notes were issued to repay amounts owed by the pipeline companies to fund the cost of construction of the Bakken Pipeline system. If the pipeline were temporarily shut down, MPLX would have to contribute its 9.19 percent pro rata share of funds required to pay interest accruing on the notes and any portion of the principal that matures while the pipeline is shutdown. MPLX also expects to contribute its 9.19 percent pro rata share of any costs to remediate any deficiencies to reinstate the permit and/or return the pipeline into operation. If the vacatur of the easement permit results in a permanent shutdown of the pipeline, MPLX would have to contribute its 9.19 percent pro rata share of the cost to redeem the bonds (including the 1 percent redemption premium required pursuant to the indenture governing the notes) and any accrued and unpaid interest. As of June 30, 2023, our maximum potential undiscounted payments under the Contingent Equity Contribution Agreement were approximately $170 million. Crowley Blue Water Partners LLC In connection with our 50 percent indirect interest in Crowley Blue Water Partners LLC, we have agreed to provide a conditional guarantee of up to 50 percent of its outstanding debt balance in the event there is no charter agreement in place with an investment grade customer for the entity’s three vessels as well as other financial support in certain circumstances. As of June 30, 2023, our maximum potential undiscounted payments under this arrangement were $97 million. Other guarantees We have entered into other guarantees with maximum potential undiscounted payments totaling $124 million as of June 30, 2023, which primarily consist of a commitment to contribute cash to an equity method investee for certain catastrophic events in lieu of procuring insurance coverage, a commitment to fund a share of the bonds issued by a government entity for construction of public utilities in the event that other industrial users of the facility default on their utility payments, a commitment to pay a termination fee on a supply agreement if terminated during the initial term, and leases of assets containing general lease indemnities and guaranteed residual values. Contractual Commitments and Contingencies

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Pay vs Performance Disclosure
Net Income (Loss) Attributable to Parent	$ 2,226	$ 5,873	$ 4,950	$ 6,718

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Jun. 30, 2023
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	During the quarter ended June 30, 2023, no director or officer (as defined in Rule 16a-1(f) promulgated under the Exchange Act) of MPC adopted or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement” (as each term is defined in Item 408 of Regulation S-K).
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Description of the Business a_2

Description of the Business and Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Use of estimates	These interim consolidated financial statements are unaudited; however, in the opinion of our management, these statements reflect all adjustments necessary for a fair statement of the results for the periods reported. All such adjustments are of a normal, recurring nature unless otherwise disclosed. These interim consolidated financial statements, including the notes, have been prepared in accordance with the rules of the SEC applicable to interim period financial statements and do not include all of the information and disclosures required by GAAP for complete financial statements. Certain information and disclosures derived from our audited annual financial statements, prepared in accordance with GAAP, have been condensed or omitted from these interim financial statements.
Inventories	Inventories are carried at the lower of cost or market value. Costs of crude oil and refined products are aggregated on a consolidated basis for purposes of assessing whether the LIFO cost basis of these inventories may have to be written down to market values.
Derivative instruments	Derivatives that are not designated as accounting hedges may include commodity derivatives used to hedge price risk on (1) inventories, (2) fixed price sales of refined products, (3) the acquisition of foreign-sourced crude oil, (4) the acquisition of ethanol for blending with refined products, (5) the sale of NGLs, (6) the purchase of natural gas, (7) the purchase of soybean oil and (8) the sale of propane.

Short-term Investments (Tables)

Short-term Investments (Tables)	6 Months Ended
	Jun. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-sale Securities Reconciliation	The components of investments were as follows: June 30, 2023 (Millions of dollars) Fair Value Level Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash and Cash Equivalents Short-term Investments Available-for-sale debt securities Commercial paper Level 2 $ 2,088 $ — $ (1) $ 2,087 $ 447 $ 1,640 Certificates of deposit and time deposits Level 2 3,340 — (1) 3,339 2,562 777 U.S. government securities Level 1 1,965 — (4) 1,961 309 1,652 Corporate notes and bonds Level 2 40 — — 40 — 40 Total available-for-sale debt securities $ 7,433 $ — $ (6) $ 7,427 $ 3,318 $ 4,109 Cash 4,027 4,027 — Total $ 11,454 $ 7,345 $ 4,109 December 31, 2022 (Millions of dollars) Fair Value Level Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash and Cash Equivalents Short-term Investments Available-for-sale debt securities Commercial paper Level 2 $ 3,074 $ — $ (1) $ 3,073 $ 1,106 $ 1,967 Certificates of deposit and time deposits Level 2 2,093 — — 2,093 1,500 593 U.S. government securities Level 1 1,071 — — 1,071 498 573 Corporate notes and bonds Level 2 66 — — 66 54 12 Total available-for-sale debt securities $ 6,304 $ — $ (1) $ 6,303 $ 3,158 $ 3,145 Cash 5,467 5,467 — Total $ 11,770 $ 8,625 $ 3,145

Master Limited Partnership (Tab

Master Limited Partnership (Tables)	6 Months Ended
	Jun. 30, 2023
Noncontrolling Interest [Line Items]
Unit Repurchases	Total share repurchases were as follows for the respective periods: Three Months Ended Six Months Ended (In millions, except per share data) 2023 2022 2023 2022 Number of shares repurchased 26 34 51 71 Cash paid for shares repurchased $ 3,068 $ 3,331 $ 6,248 $ 6,177 Average cost per share (a) $ 117.62 $ 95.46 $ 122.07 $ 85.31 (a) The average cost per share for the 2023 period includes a 1% excise tax on share repurchases resulting from the Inflation Reduction Act of 2022 .
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net	As a result of equity transactions of MPLX, we are required to adjust non-controlling interest and additional paid-in capital. Changes in MPC’s additional paid-in capital resulting from changes in its ownership interests in MPLX were as follows: Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Increase (decrease) due to change in ownership $ — $ (13) $ 1 $ (50) Tax impact — (7) 2 5 Increase (decrease) in MPC's additional paid-in capital, net of tax $ — $ (20) $ 3 $ (45)
MPLX LP
Noncontrolling Interest [Line Items]
Unit Repurchases	Total unit repurchases were as follows for the respective periods: Three Months Ended Six Months Ended (In millions, except per share data) 2023 2022 2023 2022 Number of common units repurchased — 1 — 4 Cash paid for common units repurchased $ — $ 35 $ — $ 135 Average cost per unit $ — $ 33.74 $ — $ 32.48

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	6 Months Ended
	Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Variable Interest Entities	The following table presents balance sheet information for the assets and liabilities of MPLX, which are included in our consolidated balance sheets. (Millions of dollars) June 30, December 31, Assets Cash and cash equivalents $ 755 $ 238 Receivables, less allowance for doubtful accounts 728 747 Inventories 146 148 Other current assets 52 56 Equity method investments 4,124 4,095 Property, plant and equipment, net 18,692 18,848 Goodwill 7,645 7,645 Right of use assets 281 283 Other noncurrent assets 1,611 1,664 Liabilities Accounts payable $ 588 $ 664 Payroll and benefits payable — 4 Accrued taxes 82 67 Debt due within one year 1 988 Operating lease liabilities 49 46 Other current liabilities 331 338 Long-term debt 20,405 18,808 Deferred income taxes 13 13 Long-term operating lease liabilities 228 230 Deferred credits and other liabilities 385 366

Related Party Transactions (Tab

Related Party Transactions (Tables)	6 Months Ended
	Jun. 30, 2023
Related Party Transactions [Abstract]
Related Party Transactions	Transactions with related parties were as follows: Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Sales to related parties $ 263 $ 21 $ 452 $ 40 Purchases from related parties 480 297 791 579 Sales to related parties, which are included in sales and other operating revenues, consist primarily of refined product sales and renewable feedstock sales to certain of our equity affiliates.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2023
Earnings Per Share [Abstract]
Summary of Earnings Per Common Share	We compute basic earnings per share by dividing net income attributable to MPC less income allocated to participating securities by the weighted average number of shares of common stock outstanding. Since MPC grants certain incentive compensation awards to employees and non-employee directors that are considered to be participating securities, we have calculated our earnings per share using the two-class method. Diluted income per share assumes exercise of certain share-based compensation awards, provided the effect is not anti-dilutive. Three Months Ended Six Months Ended (In millions, except per share data) 2023 2022 2023 2022 Net income $ 2,580 $ 6,217 $ 5,664 $ 7,389 Net income attributable to noncontrolling interest (354) (344) (714) (671) Net income allocated to participating securities (1) (3) (3) (3) Redemption of preferred units — — (2) — Income available to common stockholders $ 2,225 $ 5,870 $ 4,945 $ 6,715 Weighted average common shares outstanding: Basic 417 532 430 549 Effect of dilutive securities 2 4 2 4 Diluted 419 536 432 553 Income available to common stockholders per share: Basic: Net income attributable to MPC per share $ 5.34 $ 11.03 $ 11.49 $ 12.24 Diluted: Net income attributable to MPC per share $ 5.32 $ 10.95 $ 11.44 $ 12.15
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following table summarizes the shares that were anti-dilutive and, therefore, were excluded from the diluted share calculation. Three Months Ended Six Months Ended (In millions) 2023 2022 2023 2022 Shares issuable under share-based compensation plans — — — —

Equity (Tables)

Equity (Tables)	6 Months Ended
	Jun. 30, 2023
Equity [Abstract]
Share Repurchases	Total share repurchases were as follows for the respective periods: Three Months Ended Six Months Ended (In millions, except per share data) 2023 2022 2023 2022 Number of shares repurchased 26 34 51 71 Cash paid for shares repurchased $ 3,068 $ 3,331 $ 6,248 $ 6,177 Average cost per share (a) $ 117.62 $ 95.46 $ 122.07 $ 85.31 (a) The average cost per share for the 2023 period includes a 1% excise tax on share repurchases resulting from the Inflation Reduction Act of 2022 .

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2023
Segment Reporting [Abstract]
Adjusted EBITDA	Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Segment adjusted EBITDA for reportable segments Refining & Marketing $ 3,163 $ 7,760 $ 7,016 $ 9,134 Midstream 1,532 1,456 3,062 2,859 Total reportable segments $ 4,695 $ 9,216 $ 10,078 $ 11,993 Reconciliation of segment adjusted EBITDA for reportable segments to income before income taxes Total reportable segments $ 4,695 $ 9,216 $ 10,078 $ 11,993 Corporate (164) (156) (329) (294) Refining planned turnaround costs (392) (151) (749) (296) Renewable volume obligation requirements — 238 — 238 Litigation — — — 27 Depreciation and amortization (834) (819) (1,634) (1,624) Net interest and other financial costs (142) (312) (296) (574) Income before income taxes $ 3,163 $ 8,016 $ 7,070 $ 9,470
Reconciliation of Revenue from Segments to Consolidated	Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Sales and other operating revenues Refining & Marketing Revenues from external customers (a) $ 35,167 $ 52,300 $ 68,830 $ 89,092 Intersegment revenues 21 47 48 83 Refining & Marketing segment revenues 35,188 52,347 68,878 89,175 Midstream Revenues from external customers (a) 1,176 1,495 2,377 2,761 Intersegment revenues 1,347 1,308 2,709 2,555 Midstream segment revenues 2,523 2,803 5,086 5,316 Total segment revenues 37,711 55,150 73,964 94,491 Less: intersegment revenues 1,368 1,355 2,757 2,638 Consolidated sales and other operating revenues (a) $ 36,343 $ 53,795 $ 71,207 $ 91,853 (a) Includes related party sales. See Note 6 for additional information.
Other Significant Reconciling Items from Segments to Consolidated	Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Income (loss) from equity method investments Refining & Marketing $ 17 $ 6 $ (19) $ 18 Midstream 182 141 351 271 Corporate — — — — Consolidated income from equity method investments $ 199 $ 147 $ 332 $ 289 Depreciation and amortization Refining & Marketing $ 484 $ 475 $ 948 $ 936 Midstream 331 330 648 661 Corporate 19 14 38 27 Consolidated depreciation and amortization $ 834 $ 819 $ 1,634 $ 1,624 Capital expenditures Refining & Marketing $ 243 $ 315 $ 664 $ 559 Midstream 273 222 514 505 Segment capital expenditures and investments 516 537 1,178 1,064 Less investments in equity method investees 89 48 296 160 Plus: Corporate 33 15 40 38 Capitalized interest 13 25 34 48 Consolidated capital expenditures (a) $ 473 $ 529 $ 956 $ 990 (a) Includes changes in capital expenditure accruals. See Note 19 for a reconciliation of total capital expenditures to additions to property, plant and equipment for the six months ended June 30, 2023 and 2022 as reported in the consolidated statements of cash flows.

Net Interest and Other Financ_2

Net Interest and Other Financial Costs (Tables)	6 Months Ended
	Jun. 30, 2023
Other Income and Expenses [Abstract]
Net Interest And Other Financial Income (Costs)	Net interest and other financial costs were as follows: Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Interest income $ (119) $ (18) $ (240) $ (23) Interest expense 329 324 663 634 Interest capitalized (13) (25) (36) (48) Pension and other postretirement non-service costs (a) (25) 32 (48) 11 Loss on extinguishment of debt — — 9 — Investments - net premium (discount) amortization (31) (5) (59) (6) Other financial costs 1 4 7 6 Net interest and other financial costs $ 142 $ 312 $ 296 $ 574 (a) See Note 22.

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Jun. 30, 2023
Inventory Disclosure [Abstract]
Summary Of Inventories	(Millions of dollars) June 30, December 31, Crude oil $ 3,279 $ 3,047 Refined products 5,254 4,748 Materials and supplies 1,003 1,032 Total $ 9,536 $ 8,827

Property, Plant and Equipment_2

Property, Plant and Equipment (PP&E) (Tables)	6 Months Ended
	Jun. 30, 2023
Property, Plant and Equipment [Abstract]
Summary Of Property, Plant And Equipment	June 30, 2023 December 31, 2022 (Millions of dollars) Gross Accumulated Depreciation Net Gross Accumulated Depreciation Net Refining & Marketing $ 32,712 $ 17,576 $ 15,136 $ 32,292 $ 16,745 $ 15,547 Midstream 28,043 8,689 19,354 27,659 8,118 19,541 Corporate 1,589 1,020 569 1,550 981 569 Total $ 62,344 $ 27,285 $ 35,059 $ 61,501 $ 25,844 $ 35,657

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Assets and Liabilities Accounted for at Fair Value on Recurring Basis	The following tables present assets and liabilities accounted for at fair value on a recurring basis as of June 30, 2023 and December 31, 2022 by fair value hierarchy level. We have elected to offset the fair value amounts recognized for multiple derivative contracts executed with the same counterparty, including any related cash collateral as shown below; however, fair value amounts by hierarchy level are presented on a gross basis in the following tables. June 30, 2023 Fair Value Hierarchy (Millions of dollars) Level 1 Level 2 Level 3 Netting and Collateral (a) Net Carrying Value on Balance Sheet (b) Collateral Pledged Not Offset Assets: Commodity contracts $ 338 $ 10 $ — $ (330) $ 18 $ 53 Liabilities: Commodity contracts $ 361 $ — $ — $ (361) $ — $ — Embedded derivatives in commodity contracts — — 53 — 53 — December 31, 2022 Fair Value Hierarchy (Millions of dollars) Level 1 Level 2 Level 3 Netting and Collateral (a) Net Carrying Value on Balance Sheet (b) Collateral Pledged Not Offset Assets: Commodity contracts $ 310 $ — $ — $ (243) $ 67 $ 100 Liabilities: Commodity contracts $ 301 $ — $ — $ (301) $ — $ — Embedded derivatives in commodity contracts — — 61 — 61 — (a) Represents the impact of netting assets, liabilities and cash collateral when a legal right of offset exists. As of June 30, 2023, cash collateral of $31 million was netted with mark-to-market derivative liabilities. As of December 31, 2022, cash collateral of $58 million was netted with mark-to-market derivative liabilities. (b) We have no derivative contracts which are subject to master netting arrangements reflected gross on the balance sheet.
Reconciliation of Net Beginning and Ending Balances Recorded for Net Assets and Liabilities Classified as Level 3	The following is a reconciliation of the beginning and ending balances recorded for net liabilities classified as Level 3 in the fair value hierarchy. Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Beginning balance $ 58 $ 99 $ 61 $ 108 Unrealized and realized gain included in net income (3) (4) (3) (8) Settlements of derivative instruments (2) (3) (5) (8) Ending balance $ 53 $ 92 $ 53 $ 92 The amount of total gain for the period included in earnings attributable to the change in unrealized losses relating to liabilities still held at the end of period: $ (3) $ (3) $ (3) $ (8)

Derivatives (Tables)

Derivatives (Tables)	6 Months Ended
	Jun. 30, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Classification of Fair Values of Derivative Instruments, Excluding Cash Collateral	The following table presents the fair value of derivative instruments as of June 30, 2023 and December 31, 2022 and the line items in the consolidated balance sheets in which the fair values are reflected. The fair value amounts below are presented on a gross basis and do not reflect the netting of asset and liability positions permitted under the terms of our master netting arrangements including cash collateral on deposit with, or received from, brokers. We offset the recognized fair value amounts for multiple derivative instruments executed with the same counterparty in our financial statements when a legal right of offset exists. As a result, the asset and liability amounts below will not agree with the amounts presented in our consolidated balance sheets. (Millions of dollars) June 30, 2023 December 31, 2022 Balance Sheet Location Asset Liability Asset Liability Commodity derivatives Other current assets $ 348 $ 361 $ 310 $ 301 Other current liabilities (a) — 7 — 10 Deferred credits and other liabilities (a) — 46 — 51 (a) Includes embedded derivatives.
Open Commodity Derivative Contracts	The table below summarizes open commodity derivative contracts for crude oil, refined products, blending products, soybean oil and propane as of June 30, 2023. Percentage of contracts that expire next quarter Position (Units in thousands of barrels) Long Short Exchange-traded (a) Crude oil 53.1% 74,081 79,120 Refined products 86.9% 15,695 14,661 Blending products 49.6% 1,958 4,433 Soybean oil 76.6% 4,610 5,150 Over-the-counter Propane 50.5% — 809 (a) Included in exchange-traded are spread contracts in thousands of barrels: Crude oil - 20,150 long and 20,500 short; Refined products - 2,449 long and 995 short. There are no spread contracts for blending products or soybean oil.
Effect of Commodity Derivative Instruments in Statements of Income	The following table summarizes the effect of all commodity derivative instruments in our consolidated statements of income: Gain (Loss) (Millions of dollars) Three Months Ended Six Months Ended Income Statement Location 2023 2022 2023 2022 Sales and other operating revenues $ 8 $ — $ 10 $ — Cost of revenues 50 17 111 (325) Other income — (1) 1 1 Total $ 58 $ 16 $ 122 $ (324)

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 30, 2023
Debt Disclosure [Abstract]
Outstanding Borrowings	Our outstanding borrowings at June 30, 2023 and December 31, 2022 consisted of the following: (Millions of dollars) June 30, December 31, Marathon Petroleum Corporation: Senior notes $ 6,449 $ 6,449 Notes payable 1 1 Finance lease obligations 493 522 Total 6,943 6,972 MPLX LP: Senior notes 20,700 20,100 Finance lease obligations 7 8 Total 20,707 20,108 Total debt 27,650 27,080 Unamortized debt issuance costs (150) (142) Unamortized discount, net of unamortized premium (217) (238) Amounts due within one year (72) (1,066) Total long-term debt due after one year $ 27,211 $ 25,634
Schedule of Line of Credit Facilities	Available Capacity under our Credit Facilities as of June 30, 2023 (Millions of dollars) Total Outstanding Outstanding Available Weighted Expiration MPC, excluding MPLX MPC bank revolving credit facility $ 5,000 $ — $ 1 $ 4,999 — % July 2027 MPC trade receivables securitization facility (a) 100 — 100 — — September 2023 MPLX MPLX bank revolving credit facility 2,000 — — 2,000 — % July 2027 (a) The committed borrowing and letter of credit issuance capacity of the trade receivables securitization facility is $100 million. In addition, the facility allows for the issuance of letters of credit in excess of the committed capacity at the discretion of the issuing banks. As of June 30, 2023, letters of credit in the total amount of $386 million were issued and outstanding under the facility to secure contracts awarded by the Department of Energy to purchase crude oil from the Strategic Petroleum Reserve.

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Jun. 30, 2023
Revenue from Contract with Customer [Abstract]
Revenue from External Customers by Products and Services	The following table presents our revenues from external customers disaggregated by segment and product line. Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Refining & Marketing Refined products $ 32,864 $ 48,864 $ 64,787 $ 82,457 Crude oil 1,875 2,976 3,205 5,865 Services and other 428 460 838 770 Total revenues from external customers 35,167 52,300 68,830 89,092 Midstream Refined products 377 698 797 1,195 Services and other 799 797 1,580 1,566 Total revenues from external customers 1,176 1,495 2,377 2,761 Sales and other operating revenues $ 36,343 $ 53,795 $ 71,207 $ 91,853

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	6 Months Ended
	Jun. 30, 2023
Supplemental Cash Flow Elements [Abstract]
Summary of Supplemental Cash Flow Information	Six Months Ended (Millions of dollars) 2023 2022 Net cash provided by operating activities included: Interest paid (net of amounts capitalized) $ 584 $ 519 Net income taxes paid to (received from) taxing authorities 1,400 1,123 Non-cash investing and financing activities: Book value of equity method investment (a) — 25 (a) Represents the book value of MPC’s equity method investment in Watson Cogeneration Company at June 1, 2022. See Note 13 for additional information.
Reconciliation of Additions to Property, Plant and Equipment to Total Capital Expenditures	The consolidated statements of cash flows exclude changes to the consolidated balance sheets that did not affect cash. The following is a reconciliation of additions to property, plant and equipment to total capital expenditures: Six Months Ended (Millions of dollars) 2023 2022 Additions to property, plant and equipment per the consolidated statements of cash flows $ 938 $ 993 Increase (decrease) in capital accruals 18 (3) Total capital expenditures $ 956 $ 990

Other Current Liabilities (Tabl

Other Current Liabilities (Tables)	6 Months Ended
	Jun. 30, 2023
Other Liabilities Disclosure [Abstract]
Other Current Liabilities	The following summarizes the components of other current liabilities: (Millions of dollars) June 30, December 31, Environmental credits liability $ 1,135 $ 429 Accrued interest payable 325 315 Other current liabilities 587 423 Total other current liabilities $ 2,047 $ 1,167

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	6 Months Ended
	Jun. 30, 2023
Equity [Abstract]
Changes in Accumulated Other Comprehensive Loss by Component	The following table shows the changes in accumulated other comprehensive income (loss) by component. Amounts in parentheses indicate debits. (Millions of dollars) Pension Benefits Other Benefits Other Total Balance as of December 31, 2021 $ (117) $ 49 $ 1 $ (67) Other comprehensive gain (loss) before reclassifications, net of tax of $(8) (19) 3 (6) (22) Amounts reclassified from accumulated other comprehensive loss: Amortization of prior service credit (a) (23) (11) — (34) Amortization of actuarial loss (a) 7 3 — 10 Settlement loss (a) 56 — — 56 Tax effect (10) 2 — (8) Other comprehensive income (loss) 11 (3) (6) 2 Balance as of June 30, 2022 $ (106) $ 46 $ (5) $ (65) (Millions of dollars) Pension Benefits Other Benefits Other Total Balance as of December 31, 2022 $ (163) $ 165 $ — $ 2 Other comprehensive gain (loss) before reclassifications, net of tax of $0 (4) 3 (3) (4) Amounts reclassified from accumulated other comprehensive loss: Amortization of prior service credit (a) (22) (11) — (33) Amortization of actuarial gain (a) (3) — — (3) Settlement loss (a) (2) — — (2) Tax effect 7 3 — 10 Other comprehensive loss (24) (5) (3) (32) Balance as of June 30, 2023 $ (187) $ 160 $ (3) $ (30) (a) These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. See Note 22.

Pension and Other Postretirem_2

Pension and Other Postretirement Benefits (Tables)	6 Months Ended
	Jun. 30, 2023
Retirement Benefits [Abstract]
Components of Net Periodic Benefit Costs	The following summarizes the components of net periodic benefit costs: Three Months Ended Six Months Ended (Millions of dollars) 2023 2022 2023 2022 Pension Benefits Service cost $ 48 $ 65 $ 97 $ 133 Interest cost 29 24 58 47 Expected return on plan assets (42) (37) (84) (78) Amortization of prior service credit (11) (12) (22) (23) Amortization of actuarial (gain) loss (1) 3 (3) 7 Settlement loss (2) 54 (2) 56 Net periodic pension benefit cost $ 21 $ 97 $ 44 $ 142 Other Benefits Service cost $ 5 $ 5 $ 10 $ 13 Interest cost 8 5 16 10 Amortization of prior service credit (6) (6) (11) (11) Amortization of actuarial loss — 1 — 3 Net periodic other benefit cost $ 7 $ 5 $ 15 $ 15

Short-term Investments (Compone

Short-term Investments (Components of Investments) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized cost of available-for-sale debt securities	$ 7,433	$ 6,304
Unrealized gains, available-for-sale debt securities	0	0
Unrealized losses, available-for-sale debt securities	(6)	(1)
Fair value of available-for-sale debt securities	7,427	6,303
Cash	4,027	5,467
Short-term investments and cash	11,454	11,770
Commercial Paper [Member] | Level 2
Debt Securities, Available-for-sale [Line Items]
Amortized cost of available-for-sale debt securities	2,088	3,074
Unrealized gains, available-for-sale debt securities	0	0
Unrealized losses, available-for-sale debt securities	(1)	(1)
Fair value of available-for-sale debt securities	2,087	3,073
Certificates of deposit and time deposits | Level 2
Debt Securities, Available-for-sale [Line Items]
Amortized cost of available-for-sale debt securities	3,340	2,093
Unrealized gains, available-for-sale debt securities	0	0
Unrealized losses, available-for-sale debt securities	(1)	0
Fair value of available-for-sale debt securities	3,339	2,093
U.S. government securities | Level 1
Debt Securities, Available-for-sale [Line Items]
Amortized cost of available-for-sale debt securities	1,965	1,071
Unrealized gains, available-for-sale debt securities	0	0
Unrealized losses, available-for-sale debt securities	(4)	0
Fair value of available-for-sale debt securities	1,961	1,071
Corporate notes and bonds | Level 2
Debt Securities, Available-for-sale [Line Items]
Amortized cost of available-for-sale debt securities	40	66
Unrealized gains, available-for-sale debt securities	0	0
Unrealized losses, available-for-sale debt securities	0	0
Fair value of available-for-sale debt securities	40	66
Cash and Cash Equivalents
Debt Securities, Available-for-sale [Line Items]
Fair value of available-for-sale debt securities	3,318	3,158
Cash	4,027	5,467
Short-term investments and cash	7,345	8,625
Cash and Cash Equivalents | Commercial Paper [Member] | Level 2
Debt Securities, Available-for-sale [Line Items]
Fair value of available-for-sale debt securities	447	1,106
Cash and Cash Equivalents | Certificates of deposit and time deposits | Level 2
Debt Securities, Available-for-sale [Line Items]
Fair value of available-for-sale debt securities	2,562	1,500
Cash and Cash Equivalents | U.S. government securities | Level 1
Debt Securities, Available-for-sale [Line Items]
Fair value of available-for-sale debt securities	309	498
Cash and Cash Equivalents | Corporate notes and bonds | Level 2
Debt Securities, Available-for-sale [Line Items]
Fair value of available-for-sale debt securities	0	54
Short-term Investments
Debt Securities, Available-for-sale [Line Items]
Fair value of available-for-sale debt securities	4,109	3,145
Cash	0	0
Short-term investments and cash	4,109	3,145
Short-term Investments | Commercial Paper [Member] | Level 2
Debt Securities, Available-for-sale [Line Items]
Fair value of available-for-sale debt securities	1,640	1,967
Short-term Investments | Certificates of deposit and time deposits | Level 2
Debt Securities, Available-for-sale [Line Items]
Fair value of available-for-sale debt securities	777	593
Short-term Investments | U.S. government securities | Level 1
Debt Securities, Available-for-sale [Line Items]
Fair value of available-for-sale debt securities	1,652	573
Short-term Investments | Corporate notes and bonds | Level 2
Debt Securities, Available-for-sale [Line Items]
Fair value of available-for-sale debt securities	$ 40	$ 12

Master Limited Partnership (Det

Master Limited Partnership (Details)	Jun. 30, 2023
MPLX | Marathon Petroleum Corporation
MPC's partnership interest in MLP (in percentage)	65%

Master Limited Partnership (Uni

Master Limited Partnership (Unit Repurchase Program) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2023		Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Aug. 02, 2022	Nov. 02, 2020
Units acquired, average cost per unit	$ 117.62	[1]	$ 95.46	$ 122.07	$ 85.31
Stock repurchase program, remaining authorized repurchase amount	$ 7,120			$ 7,120
Share Repurchase Authorization August 2022
Stock repurchase program, authorized amount						$ 5,000
MPLX LP
Units repurchased, units	0		1	0	4
Units repurchased, value	$ 0		$ 35	$ 0	$ 135
Units acquired, average cost per unit	$ 0		$ 33.74	$ 0	$ 32.48
Stock repurchase program, remaining authorized repurchase amount	$ 846			$ 846
MPLX LP | Share Repurchase Authorization November 2020
Stock repurchase program, authorized amount							$ 1,000
MPLX LP | Share Repurchase Authorization August 2022
Stock repurchase program, authorized amount						$ 1,000
[1] The average cost per share for the 2023 period includes a 1% excise tax on share repurchases resulting from the Inflation Reduction Act of 2022 .

Master Limited Partnership (Red

Master Limited Partnership (Redemption of the Series B Preferred Units) (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		6 Months Ended
	Feb. 15, 2023	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Noncontrolling Interest [Line Items]
Redemption of noncontrolling interests - preferred units				$ 600	$ 0
Redemption of preferred units		$ 0	$ 0	$ 2	$ 0
MPLX | Series B Preferred Stock
Noncontrolling Interest [Line Items]
Preferred units, outstanding	600,000
Preferred units, redemption price per unit	$ 1,000
Redemption of noncontrolling interests - preferred units	$ 600
Redemption of preferred units	$ 2

Master Limited Partnership (Non

Master Limited Partnership (Noncontrolling Interest) (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Equity transactions of MPLX	$ 0	$ (597)	$ (42)	$ (88)
Additional Paid-in Capital
Increase (decrease) due to change in ownership	0		(13)		$ 1	$ (50)
Tax impact	0		(7)		2	5
Equity transactions of MPLX	$ 0	$ 3	$ (20)	$ (25)	$ 3	$ (45)

Variable Interest Entities (Con

Variable Interest Entities (Consolidated VIE) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Assets
Cash and cash equivalents	$ 7,345	$ 8,625
Receivables, less allowance for doubtful accounts	10,274	13,477
Inventories	9,536	8,827
Other current assets	949	1,168
Equity method investments	6,665	6,466
Property, plant and equipment, net	35,059	35,657
Goodwill	8,244	8,244
Right of use assets	1,288	1,214
Other noncurrent assets	2,973	3,081
Liabilities
Accounts payable	13,052	15,312
Payroll and benefits payable	712	967
Accrued taxes	1,160	1,140
Debt due within one year	72	1,066
Operating lease liabilities	423	368
Other current liabilities	2,047	1,167
Long-term debt	27,211	25,634
Deferred income taxes	5,913	5,904
Long-term operating lease liabilities	859	841
Deferred credits and other liabilities	1,244	1,304
Variable Interest Entity, Primary Beneficiary | MPLX
Assets
Cash and cash equivalents	755	238
Receivables, less allowance for doubtful accounts	728	747
Inventories	146	148
Other current assets	52	56
Equity method investments	4,124	4,095
Property, plant and equipment, net	18,692	18,848
Goodwill	7,645	7,645
Right of use assets	281	283
Other noncurrent assets	1,611	1,664
Liabilities
Accounts payable	588	664
Payroll and benefits payable	0	4
Accrued taxes	82	67
Debt due within one year	1	988
Operating lease liabilities	49	46
Other current liabilities	331	338
Long-term debt	20,405	18,808
Deferred income taxes	13	13
Long-term operating lease liabilities	228	230
Deferred credits and other liabilities	$ 385	$ 366

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023		Jun. 30, 2022
Related Party Transaction [Line Items]
Sales and other operating revenues	$ 36,343	$ 53,795	$ 71,207	[1]	$ 91,853	[1]
Purchases from related parties	480	297	791		579
Related Party
Related Party Transaction [Line Items]
Sales and other operating revenues	$ 263	$ 21	$ 452		$ 40
[1]Includes related party sales. See Note 6 for additional information

Earnings Per Share (Summary of

Earnings Per Share (Summary of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Earnings Per Share [Abstract]
Net income	$ 2,580	$ 6,217	$ 5,664	$ 7,389
Net income attributable to noncontrolling interest	(354)	(344)	(714)	(671)
Net income allocated to participating securities	(1)	(3)	(3)	(3)
Redemption of preferred units	0	0	(2)	0
Income available to common stockholders	$ 2,225	$ 5,870	$ 4,945	$ 6,715
Weighted average common shares outstanding:
Basic (in shares)	417	532	430	549
Effect of dilutive securities (in shares)	2	4	2	4
Diluted (in shares)	419	536	432	553
Basic:
Net income attributable to MPC per share	$ 5.34	$ 11.03	$ 11.49	$ 12.24
Diluted:
Net income attributable to MPC per share	$ 5.32	$ 10.95	$ 11.44	$ 12.15

Earnings Per Share (Anti-diluti

Earnings Per Share (Anti-dilutive Shares) (Details) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Stock Based Compensation Expense
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares issuable under share-based compensation plans	0	0	0	0

Equity (Share Repurchase Author

Equity (Share Repurchase Authorizations) (Details) - USD ($) $ in Millions	Jun. 30, 2023	May 02, 2023	Jan. 31, 2023	Aug. 02, 2022	Feb. 02, 2022	May 01, 2021
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, remaining authorized repurchase amount	$ 7,120
Share Repurchase Authorization May 2021
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount						$ 7,100
Share Repurchase Authorization February 2022
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount					$ 5,000
Share Repurchase Authorization January 2023
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount			$ 5,000
Share Repurchase Authorization August 2022
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount				$ 5,000
Share Repurchase Authorization May 2023
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount		$ 5,000

Equity (Share Repurchases) (Det

Equity (Share Repurchases) (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended			6 Months Ended
	Jul. 31, 2023	Jun. 30, 2023		Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased		26,000,000		34,000,000	51,000,000	71,000,000
Cash paid for shares repurchased		$ 3,068		$ 3,331	$ 6,248	$ 6,177
Average cost per share(a)		$ 117.62	[1]	$ 95.46	$ 122.07	$ 85.31
Subsequent Event
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased	540,000
Cash paid for shares repurchased	$ 63
[1] The average cost per share for the 2023 period includes a 1% excise tax on share repurchases resulting from the Inflation Reduction Act of 2022 .

Segment Information (Additional

Segment Information (Additional Information) (Details)	6 Months Ended
	Jun. 30, 2023 Segment
Segment Reporting [Abstract]
Number of reportable segments	2

Segment Information (Segment Ad

Segment Information (Segment Adjusted EBITDA to Income (Loss) from Continuing Operations before Income Taxes) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information [Line Items]
Refining planned turnaround costs	$ (392)	$ (151)	$ (749)	$ (296)
Renewable volume obligation requirements	0	238	0	238
Litigation	0	0	0	27
Depreciation and amortization	(834)	(819)	(1,634)	(1,624)
Net interest and other financial costs	(142)	(312)	(296)	(574)
Income before income taxes	3,163	8,016	7,070	9,470
Operating Segments
Segment Reporting Information [Line Items]
Adjusted EBITDA	4,695	9,216	10,078	11,993
Operating Segments | Refining & Marketing
Segment Reporting Information [Line Items]
Adjusted EBITDA	3,163	7,760	7,016	9,134
Depreciation and amortization	(484)	(475)	(948)	(936)
Operating Segments | Midstream
Segment Reporting Information [Line Items]
Adjusted EBITDA	1,532	1,456	3,062	2,859
Depreciation and amortization	(331)	(330)	(648)	(661)
Corporate
Segment Reporting Information [Line Items]
Costs and expenses, excluding depreciation	(164)	(156)	(329)	(294)
Depreciation and amortization	$ (19)	$ (14)	$ (38)	$ (27)

Segment Information (Reconcilia

Segment Information (Reconciliation of Segment Revenues To Sales and Other Operating Revenues) (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023		Jun. 30, 2022
Segment Reporting Information [Line Items]
Sales and other operating revenues		$ 36,343	$ 53,795	$ 71,207	[1]	$ 91,853	[1]
Refining & Marketing
Segment Reporting Information [Line Items]
Sales and other operating revenues	[1]	35,167	52,300	68,830		89,092
Midstream
Segment Reporting Information [Line Items]
Sales and other operating revenues	[1]	1,176	1,495	2,377		2,761
Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues		1,368	1,355	2,757		2,638
Intersegment Eliminations | Refining & Marketing
Segment Reporting Information [Line Items]
Sales and other operating revenues		21	47	48		83
Intersegment Eliminations | Midstream
Segment Reporting Information [Line Items]
Sales and other operating revenues		1,347	1,308	2,709		2,555
Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues		37,711	55,150	73,964		94,491
Operating Segments | Refining & Marketing
Segment Reporting Information [Line Items]
Sales and other operating revenues		35,188	52,347	68,878		89,175
Operating Segments | Midstream
Segment Reporting Information [Line Items]
Sales and other operating revenues		$ 2,523	$ 2,803	$ 5,086		$ 5,316
[1]Includes related party sales. See Note 6 for additional information

Segment Information (Income fro

Segment Information (Income from Equity Method Investments) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Reconciliation Of Segment Capital Expenditures And Investments To Total Capital Expenditures [Line Items]
Income from equity method investments	$ 199	$ 147	$ 332	$ 289
Operating Segments | Refining & Marketing
Reconciliation Of Segment Capital Expenditures And Investments To Total Capital Expenditures [Line Items]
Income from equity method investments	17	6	(19)	18
Operating Segments | Midstream
Reconciliation Of Segment Capital Expenditures And Investments To Total Capital Expenditures [Line Items]
Income from equity method investments	182	141	351	271
Corporate
Reconciliation Of Segment Capital Expenditures And Investments To Total Capital Expenditures [Line Items]
Income from equity method investments	$ 0	$ 0	$ 0	$ 0

Segment Information (Depreciati

Segment Information (Depreciation and Amortization) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Reconciliation Of Segment Capital Expenditures And Investments To Total Capital Expenditures [Line Items]
Depreciation and amortization	$ 834	$ 819	$ 1,634	$ 1,624
Operating Segments | Refining & Marketing
Reconciliation Of Segment Capital Expenditures And Investments To Total Capital Expenditures [Line Items]
Depreciation and amortization	484	475	948	936
Operating Segments | Midstream
Reconciliation Of Segment Capital Expenditures And Investments To Total Capital Expenditures [Line Items]
Depreciation and amortization	331	330	648	661
Corporate
Reconciliation Of Segment Capital Expenditures And Investments To Total Capital Expenditures [Line Items]
Depreciation and amortization	$ 19	$ 14	$ 38	$ 27

Segment Information (Capital Ex

Segment Information (Capital Expenditures) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Plus:
Capital expenditures	[1]	$ 473	$ 529	$ 956	$ 990
Operating Segments
Reconciliation Of Segment Capital Expenditures And Investments To Total Capital Expenditures [Line Items]
Capital expenditures and investments		516	537	1,178	1,064
Less investments in equity method investees		89	48	296	160
Operating Segments | Refining & Marketing
Reconciliation Of Segment Capital Expenditures And Investments To Total Capital Expenditures [Line Items]
Capital expenditures and investments		243	315	664	559
Operating Segments | Midstream
Reconciliation Of Segment Capital Expenditures And Investments To Total Capital Expenditures [Line Items]
Capital expenditures and investments		273	222	514	505
Corporate
Plus:
Corporate		33	15	40	38
Capitalized interest		$ 13	$ 25	$ 34	$ 48
[1]Includes changes in capital expenditure accruals. See Note 19 for a reconciliation of total capital expenditures to additions to property, plant and equipment for the six months ended June 30, 2023 and 2022 as reported in the consolidated statements of cash flows.

Net Interest and Other Financ_3

Net Interest and Other Financial Costs (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Other Income and Expenses [Abstract]
Interest income		$ (119)	$ (18)	$ (240)	$ (23)
Interest expense		329	324	663	634
Interest capitalized		(13)	(25)	(36)	(48)
Pension and other postretirement non-service costs	[1]	(25)	32	(48)	11
Loss on extinguishment of debt		0	0	9	0
Investments - net premium (discount) amortization		(31)	(5)	(59)	(6)
Other financial costs		1	4	7	6
Net interest and other financial costs		$ 142	$ 312	$ 296	$ 574
[1]See Note 22.

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 583	$ 1,799	$ 1,406	$ 2,081

Inventories (Summary of Invento

Inventories (Summary of Inventories) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Inventory Disclosure [Abstract]
Crude oil	$ 3,279	$ 3,047
Refined products	5,254	4,748
Materials and supplies	1,003	1,032
Total	$ 9,536	$ 8,827

Equity Method Investments (LF B

Equity Method Investments (LF Bioenergy Acquisition) (Details) - USD ($) $ in Millions		6 Months Ended
	Mar. 08, 2023	Jun. 30, 2023	Jun. 30, 2022
Schedule of Equity Method Investments [Line Items]
Payments to acquire businesses, net of cash acquired		$ 0	$ 74
LF Bioenergy
Schedule of Equity Method Investments [Line Items]
Ownership percentage	49.90%
Payments to acquire businesses, net of cash acquired	$ 56

Equity Method Investments (Wats

Equity Method Investments (Watson Cogeneration Company) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
	Jun. 01, 2022	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Schedule of Equity Method Investments [Line Items]
Payments to acquire businesses, net of cash acquired				$ 0	$ 74
Book value of equity method investment				0	25	[1]
Net gain on disposal of assets		$ 13	$ 39	$ 16	$ 21
Watson Cogeneration Company
Schedule of Equity Method Investments [Line Items]
Equity method investment, remaining ownership interest purchased	49%
Payments to acquire businesses, net of cash acquired	$ 59
Fair value of assets contributed	62
Book value of equity method investment	$ 25
Ownership percentage	51%
Net gain on disposal of assets	$ 37
[1]Represents the book value of MPC’s equity method investment in Watson Cogeneration Company at June 1, 2022. See Note 13 for additional information.

Property, Plant and Equipment_3

Property, Plant and Equipment (PP&E) (Summary of Property, Plant And Equipment) (Detail) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Gross PP&E	$ 62,344	$ 61,501
Accumulated Depreciation	27,285	25,844
Net PP&E	35,059	35,657
Operating Segments | Refining & Marketing
Property, Plant and Equipment [Line Items]
Gross PP&E	32,712	32,292
Accumulated Depreciation	17,576	16,745
Net PP&E	15,136	15,547
Operating Segments | Midstream
Property, Plant and Equipment [Line Items]
Gross PP&E	28,043	27,659
Accumulated Depreciation	8,689	8,118
Net PP&E	19,354	19,541
Corporate
Property, Plant and Equipment [Line Items]
Gross PP&E	1,589	1,550
Accumulated Depreciation	1,020	981
Net PP&E	$ 569	$ 569

Fair Value Measurements (Assets

Fair Value Measurements (Assets and Liabilities Accounted for at Fair Value on Recurring Basis) (Detail) - USD ($) $ in Millions		Jun. 30, 2023	Dec. 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash collateral netted with derivative liabilities		$ 31	$ 58
Fair Value, Recurring | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivative instruments, assets - netting and collateral	[1]	(330)	(243)
Derivative asset, net carrying value on balance sheet	[2]	18	67
Commodity derivative instruments, assets - collateral pledged not offset		53	100
Commodity derivative instruments, liabilities - netting and collateral	[1]	(361)	(301)
Derivative liability, net carrying value on balance sheet	[2]	0	0
Commodity derivative instruments, liabilities - collateral pledged not offset		0	0
Fair Value, Recurring | Embedded derivatives in commodity contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivative instruments, liabilities - netting and collateral		0	0
Derivative liability, net carrying value on balance sheet	[2]	53	61
Commodity derivative instruments, liabilities - collateral pledged not offset		0	0
Fair Value, Recurring | Level 1 | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivative instruments, assets - gross		338	310
Commodity derivative instruments, liabilities - gross		361	301
Fair Value, Recurring | Level 1 | Embedded derivatives in commodity contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivative instruments, liabilities - gross		0	0
Fair Value, Recurring | Level 2 | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivative instruments, assets - gross		10	0
Commodity derivative instruments, liabilities - gross		0	0
Fair Value, Recurring | Level 2 | Embedded derivatives in commodity contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivative instruments, liabilities - gross		0	0
Fair Value, Recurring | Level 3 | Commodity derivatives
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivative instruments, assets - gross		0	0
Commodity derivative instruments, liabilities - gross		0	0
Fair Value, Recurring | Level 3 | Embedded derivatives in commodity contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivative instruments, liabilities - gross		$ 53	$ 61
[1]Represents the impact of netting assets, liabilities and cash collateral when a legal right of offset exists. As of June 30, 2023, cash collateral of $31 million was netted with mark-to-market derivative liabilities. As of December 31, 2022, cash collateral of $58 million was netted with mark-to-market derivative liabilities.[2]We have no derivative contracts which are subject to master netting arrangements reflected gross on the balance sheet.

Fair Value Measurements (Level

Fair Value Measurements (Level 3) (Details)	6 Months Ended
	Jun. 30, 2023 USD ($) $ / gal
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Term of contract	5 years
Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Average forward price | $ / gal	0.72
Probability of renewal second term	100%
Level 3 | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Forward commodity price	0.54
Level 3 | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Forward commodity price	1.34

Fair Value Measurements (Reconc

Fair Value Measurements (Reconciliation of Net Beginning and Ending Balances Recorded for Net Assets and Liabilities Classified as Level 3) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 58	$ 99	$ 61	$ 108
Unrealized and realized gain included in net income	(3)	(4)	(3)	(8)
Settlements of derivative instruments	(2)	(3)	(5)	(8)
Ending balance	$ 53	$ 92	$ 53	$ 92

Fair Value Measurements (Gain_L

Fair Value Measurements (Gain/Loss Included in Earnings Relating to Assets Still Held at End of Period) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Fair Value Disclosures [Abstract]
The amount of total gain for the period included in earnings attributable to the change in unrealized losses relating to liabilities still held at the end of period:	$ (3)	$ (3)	$ (3)	$ (8)

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Values - Reported) (Detail) - USD ($) $ in Billions	Jun. 30, 2023	Dec. 31, 2022
Reported Value Measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	$ 26.9	$ 26.3
Estimate of Fair Value Measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	$ 24.5	$ 24

Derivatives (Classification of

Derivatives (Classification of Gross Fair Values of Derivative Instruments, Excluding Cash Collateral) (Detail) - USD ($) $ in Millions		Jun. 30, 2023	Dec. 31, 2022
Commodity derivatives | Other current assets
Derivative [Line Items]
Asset		$ 348	$ 310
Liability		361	301
Embedded derivatives in commodity contracts | Other current liabilities
Derivative [Line Items]
Asset		0	0
Liability	[1]	7	10
Embedded derivatives in commodity contracts | Deferred credits and other liabilities
Derivative [Line Items]
Asset		0	0
Liability	[1]	$ 46	$ 51
[1]Includes embedded derivatives.

Derivatives (Open Commodity Der

Derivatives (Open Commodity Derivative Contracts) (Details) bbl in Thousands	6 Months Ended
	Jun. 30, 2023 bbl
Exchange Traded | Crude oil
Derivative [Line Items]
Percentage of derivative contracts expiring in the period	53.10%
Exchange Traded | Crude oil | Long
Derivative [Line Items]
Notional contracts (in thousands of total barrels)	74,081
Exchange Traded | Crude oil | Long | Spread Contracts
Derivative [Line Items]
Notional contracts (in thousands of total barrels)	20,150
Exchange Traded | Crude oil | Short
Derivative [Line Items]
Notional contracts (in thousands of total barrels)	79,120
Exchange Traded | Crude oil | Short | Spread Contracts
Derivative [Line Items]
Notional contracts (in thousands of total barrels)	20,500
Exchange Traded | Refined products
Derivative [Line Items]
Percentage of derivative contracts expiring in the period	86.90%
Exchange Traded | Refined products | Long
Derivative [Line Items]
Notional contracts (in thousands of total barrels)	15,695
Exchange Traded | Refined products | Long | Spread Contracts
Derivative [Line Items]
Notional contracts (in thousands of total barrels)	2,449
Exchange Traded | Refined products | Short
Derivative [Line Items]
Notional contracts (in thousands of total barrels)	14,661
Exchange Traded | Refined products | Short | Spread Contracts
Derivative [Line Items]
Notional contracts (in thousands of total barrels)	995
Exchange Traded | Blending products
Derivative [Line Items]
Percentage of derivative contracts expiring in the period	49.60%
Exchange Traded | Blending products | Long
Derivative [Line Items]
Notional contracts (in thousands of total barrels)	1,958
Exchange Traded | Blending products | Short
Derivative [Line Items]
Notional contracts (in thousands of total barrels)	4,433
Exchange Traded | Soybean oil
Derivative [Line Items]
Percentage of derivative contracts expiring in the period	76.60%
Exchange Traded | Soybean oil | Long
Derivative [Line Items]
Notional contracts (in thousands of total barrels)	4,610
Exchange Traded | Soybean oil | Short
Derivative [Line Items]
Notional contracts (in thousands of total barrels)	5,150
Over-the-Counter | Propane
Derivative [Line Items]
Percentage of derivative contracts expiring in the period	50.50%
Over-the-Counter | Propane | Long
Derivative [Line Items]
Notional contracts (in thousands of total barrels)	0
Over-the-Counter | Propane | Short
Derivative [Line Items]
Notional contracts (in thousands of total barrels)	809

Derivatives (Effect of Commodit

Derivatives (Effect of Commodity Derivative Instruments in Statements of Income) (Detail) - Commodity derivatives - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss)	$ 58	$ 16	$ 122	$ (324)
Sales and other operating revenues
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss)	8	0	10	0
Cost of revenues
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss)	50	17	111	(325)
Other income
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss)	$ 0	$ (1)	$ 1	$ 1

Debt (Outstanding Borrowings) (

Debt (Outstanding Borrowings) (Detail) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Total debt	$ 27,650	$ 27,080
Unamortized debt issuance costs	(150)	(142)
Unamortized discount, net of unamortized premium	(217)	(238)
Amounts due within one year	(72)	(1,066)
Total long-term debt due after one year	27,211	25,634
Marathon Petroleum Corporation:
Finance lease obligations	493	522
Total debt	6,943	6,972
Marathon Petroleum Corporation: | Senior notes
Long-term debt, gross	6,449	6,449
Marathon Petroleum Corporation: | Notes payable
Long-term debt, gross	1	1
MPLX LP:
Finance lease obligations	7	8
Total debt	20,707	20,108
MPLX LP: | Senior notes
Long-term debt, gross	$ 20,700	$ 20,100

Debt (MPLX Senior Notes) (Detai

Debt (MPLX Senior Notes) (Details) - USD ($) $ in Millions			3 Months Ended		6 Months Ended
	Mar. 13, 2023	Feb. 15, 2023	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Feb. 09, 2023
Debt Instrument [Line Items]
Redemption of noncontrolling interests - preferred units					$ 600	$ 0
Loss on extinguishment of debt			$ 0	$ 0	9	$ 0
MPLX | Series B Preferred Stock
Debt Instrument [Line Items]
Redemption of noncontrolling interests - preferred units		$ 600
MPLX LP: | MPLX | Series B Preferred Stock
Debt Instrument [Line Items]
Redemption of noncontrolling interests - preferred units		$ 600
Senior notes | MPLX LP:
Debt Instrument [Line Items]
Debt instrument, face amount							$ 1,600
Senior notes | 5.000% senior notes due March 2033 | MPLX LP:
Debt Instrument [Line Items]
Debt instrument, face amount							1,100
Senior notes | 5.650% senior notes due March 2053 | MPLX LP:
Debt Instrument [Line Items]
Debt instrument, face amount							$ 500
Senior notes | 4.500% senior notes due July 2023
Debt Instrument [Line Items]
Loss on extinguishment of debt					$ 9
Senior notes | 4.500% senior notes due July 2023 | MPLX LP:
Debt Instrument [Line Items]
Repayments of debt	$ 1,000

Debt (Available Capacity under

Debt (Available Capacity under our Facilities) (Details) $ in Millions	Jun. 30, 2023 USD ($)
MPC bank revolving credit facility due July 2027
Debt Instrument [Line Items]
Total Capacity	$ 5,000
Outstanding Borrowings	0
Outstanding Letters of Credit	1
Available Capacity	$ 4,999
Weighted Average Interest Rate	0%
MPC trade receivables securitization facility
Debt Instrument [Line Items]
Total Capacity	$ 100	[1]
Outstanding Borrowings	0
Outstanding Letters of Credit	100
Available Capacity	$ 0
Weighted Average Interest Rate	0%
Maximum borrowing capacity	$ 100
MPC trade receivables securitization facility | Purchase crude oil from Strategic Petroleum Reserve
Debt Instrument [Line Items]
Outstanding Letters of Credit	386
MPLX LP | MPLX bank revolving credit facility due July 2027
Debt Instrument [Line Items]
Total Capacity	2,000
Outstanding Borrowings	0
Outstanding Letters of Credit	0
Available Capacity	$ 2,000
Weighted Average Interest Rate	0%
[1]The committed borrowing and letter of credit issuance capacity of the trade receivables securitization facility is $100 million. In addition, the facility allows for the issuance of letters of credit in excess of the committed capacity at the discretion of the issuing banks. As of June 30, 2023, letters of credit in the total amount of $386 million were issued and outstanding under the facility to secure contracts awarded by the Department of Energy to purchase crude oil from the Strategic Petroleum Reserve.

Revenue (Disaggregated by Produ

Revenue (Disaggregated by Product Line) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023		Jun. 30, 2022
Sales and other operating revenues		$ 36,343	$ 53,795	$ 71,207	[1]	$ 91,853	[1]
Refining & Marketing
Sales and other operating revenues	[1]	35,167	52,300	68,830		89,092
Refining & Marketing | Refined products
Sales and other operating revenues		32,864	48,864	64,787		82,457
Refining & Marketing | Crude oil
Sales and other operating revenues		1,875	2,976	3,205		5,865
Refining & Marketing | Services and other
Sales and other operating revenues		428	460	838		770
Midstream
Sales and other operating revenues	[1]	1,176	1,495	2,377		2,761
Midstream | Refined products
Sales and other operating revenues		377	698	797		1,195
Midstream | Services and other
Sales and other operating revenues		$ 799	$ 797	$ 1,580		$ 1,566
[1]Includes related party sales. See Note 6 for additional information

Revenue (Details)

Revenue (Details) $ in Millions	Jun. 30, 2023 USD ($)
Revenue from Contract with Customer [Abstract]
Matching buy/sell receivables	$ 4,550

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Net cash provided by operating activities included:
Interest paid (net of amounts capitalized)	$ 584	$ 519
Net income taxes paid to (received from) taxing authorities	1,400	1,123
Non-cash investing and financing activities:
Book value of equity method investment	$ 0	$ 25	[1]
[1]Represents the book value of MPC’s equity method investment in Watson Cogeneration Company at June 1, 2022. See Note 13 for additional information.

Supplemental Cash Flow Inform_4

Supplemental Cash Flow Information (Reconciliation of Additions to Property, Plant and Equipment to Total Capital Expenditures) (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Supplemental Cash Flow Elements [Abstract]
Additions to property, plant and equipment per the consolidated statements of cash flows				$ 938	$ 993
Increase (decrease) in capital accruals				18	(3)
Capital expenditures	[1]	$ 473	$ 529	$ 956	$ 990
[1]Includes changes in capital expenditure accruals. See Note 19 for a reconciliation of total capital expenditures to additions to property, plant and equipment for the six months ended June 30, 2023 and 2022 as reported in the consolidated statements of cash flows.

Other Current Liabilities (Deta

Other Current Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Other Liabilities Disclosure [Abstract]
Environmental credits liability	$ 1,135	$ 429
Accrued interest payable	325	315
Other current liabilities	587	423
Total other current liabilities	$ 2,047	$ 1,167

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) (Changes in Accumulated Other Comprehensive Loss by Component) (Detail) - USD ($) $ in Millions		3 Months Ended				6 Months Ended
		Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			$ 2		$ (67)	$ 2	$ (67)
Other comprehensive income (loss), before reclassifications, net of tax						(4)	(22)
Amounts reclassified from accumulated other comprehensive loss:
Amortization of prior service credit						(33)	(34)
Amortization of actuarial (gain) loss						(3)	10
Settlement loss						(2)	56
Tax effect						10	(8)
Other comprehensive income (loss)		$ (21)	(11)	$ 9	(7)	(32)	2
Ending balance		(30)		(65)		(30)	(65)
Other comprehensive income (loss) before reclassifications, tax						0	(8)
Accumulated Defined Benefit Plans Adjustment | Pension Benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(163)		(117)	(163)	(117)
Other comprehensive income (loss), before reclassifications, net of tax						(4)	(19)
Amounts reclassified from accumulated other comprehensive loss:
Amortization of prior service credit	[1]					(22)	(23)
Amortization of actuarial (gain) loss	[1]					(3)	7
Settlement loss	[1]					(2)	56
Tax effect						7	(10)
Other comprehensive income (loss)						(24)	11
Ending balance		(187)		(106)		(187)	(106)
Accumulated Defined Benefit Plans Adjustment | Other Benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			165		49	165	49
Other comprehensive income (loss), before reclassifications, net of tax						3	3
Amounts reclassified from accumulated other comprehensive loss:
Amortization of prior service credit	[1]					(11)	(11)
Amortization of actuarial (gain) loss	[1]					0	3
Settlement loss						0	0
Tax effect						3	2
Other comprehensive income (loss)						(5)	(3)
Ending balance		160		46		160	46
Other
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			$ 0		$ 1	0	1
Other comprehensive income (loss), before reclassifications, net of tax						(3)	(6)
Amounts reclassified from accumulated other comprehensive loss:
Tax effect						0	0
Other comprehensive income (loss)						(3)	(6)
Ending balance		$ (3)		$ (5)		$ (3)	$ (5)
[1]These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. See Note 22.

Pension and Other Postretirem_3

Pension and Other Postretirement Benefits (Components of Net Periodic Benefit Costs) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Pension Benefits
Components of net periodic benefit cost:
Service cost	$ 48	$ 65	$ 97	$ 133
Interest cost	29	24	58	47
Expected return on plan assets	(42)	(37)	(84)	(78)
Amortization of prior service credit	(11)	(12)	(22)	(23)
Amortization of actuarial (gain) loss	(1)	3	(3)	7
Settlement loss	(2)	54	(2)	56
Net periodic benefit cost	21	97	44	142
Other Benefits
Components of net periodic benefit cost:
Service cost	5	5	10	13
Interest cost	8	5	16	10
Amortization of prior service credit	(6)	(6)	(11)	(11)
Amortization of actuarial (gain) loss	0	1	0	3
Net periodic benefit cost	$ 7	$ 5	$ 15	$ 15

Pension and Other Postretirem_4

Pension and Other Postretirement Benefits (Additional Information) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2023 USD ($)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 0
Other Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Benefits paid	7
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Benefits paid	$ 27

Commitments and Contingencies (

Commitments and Contingencies (Detail)	6 Months Ended
	Jun. 30, 2023
Pending Litigation
Loss Contingencies [Line Items]
Loss contingency, inestimable loss	For matters for which we have not recorded a liability, we are unable to estimate a range of possible loss because the issues involved have not been fully developed through pleadings, discovery or court proceedings.

Commitments and Contingencies_2

Commitments and Contingencies (Environmental Matters) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Accrued liabilities for remediation	$ 374	$ 387
Receivables for recoverable costs	$ 5	$ 5

Commitments and Contingencies_3

Commitments and Contingencies (Other Legal Proceedings) (Details) - USD ($) $ in Millions		1 Months Ended
	Dec. 15, 2020	Jul. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Loss contingency, damages sought, value		$ 187
Loss contingency, damages paid, value	$ 4

Commitments and Contingencies_4

Commitments and Contingencies (Guarantees) (Details) $ in Millions	Jun. 30, 2023 USD ($)
Other Guarantees
Loss Contingencies [Line Items]
Maximum potential undiscounted payments	$ 124
LOOP and LOCAP LLC | Guarantee of Indebtedness of Others | Financial Guarantee
Loss Contingencies [Line Items]
Maximum potential undiscounted payments	$ 171
Bakken Pipeline System | Indirect
Loss Contingencies [Line Items]
Ownership percentage	9.19%
Bakken Pipeline System | Guarantee of Indebtedness of Others | Financial Guarantee
Loss Contingencies [Line Items]
Maximum potential undiscounted payments	$ 170
Crowley Blue Water Partners
Loss Contingencies [Line Items]
Ownership percentage	50%
Crowley Blue Water Partners | Guarantee of Indebtedness of Others | Financial Guarantee
Loss Contingencies [Line Items]
Maximum potential undiscounted payments	$ 97