Delta Air Lines (DAL) 10-K 12 Feb 24 2023 FY Annual report Financial data

Cover

Cover - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2023	Jan. 31, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-5424
Entity Registrant Name	DELTA AIR LINES, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	58-0218548
Entity Address, Address Line One	Post Office Box 20706
Entity Address, City or Town	Atlanta
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30320-6001
City Area Code	404
Local Phone Number	715-2600
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	DAL
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 30.4
Entity Common Stock, Shares Outstanding		643,323,851
Documents Incorporated by Reference	Part III of this Form 10-K incorporates by reference certain information from the registrant's definitive Proxy Statement for its 2024 Annual Meeting of Stockholders to be filed with the Securities and Exchange Commission.
Entity Central Index Key	0000027904
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Amendment Flag	false

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2023
Audit Information [Abstract]
Auditor Name	Ernst & Young LLP
Auditor Location	Atlanta, Georgia
Auditor Firm ID	42

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 2,741	$ 3,266
Short-term investments	1,127	3,268
Accounts receivable, net of an allowance for uncollectible accounts of $17 and $23	3,130	3,176
Fuel, expendable parts and supplies inventories, net of an allowance for obsolescence of $123 and $136	1,314	1,424
Prepaid expenses and other	1,957	1,877
Total current assets	10,269	13,011
Noncurrent Assets:
Property and equipment, net of accumulated depreciation and amortization of $21,707 and $20,370	35,486	33,109
Operating lease right-of-use assets	7,004	7,036
Goodwill	9,753	9,753
Identifiable intangibles, net of accumulated amortization of $911 and $902	5,983	5,992
Equity investments	3,457	2,128
Other noncurrent assets	1,692	1,259
Total noncurrent assets	63,375	59,277
Total assets	73,644	72,288
Current Liabilities:
Current maturities of debt and finance leases	2,983	2,359
Current maturities of operating leases	759	714
Accounts payable	4,446	5,106
Accrued salaries and related benefits	4,561	3,288
Fuel card obligation	1,100	1,100
Other accrued liabilities	1,617	1,779
Total current liabilities	26,418	25,940
Noncurrent Liabilities:
Debt and finance leases	17,071	20,671
Pension, postretirement and related benefits	3,601	3,707
Noncurrent operating leases	6,468	6,866
Deferred income taxes, net	908	24
Other noncurrent liabilities	3,561	4,050
Total noncurrent liabilities	36,121	39,766
Commitments and Contingencies
Stockholders' Equity:
Common stock at $0.0001 par value; 1,500,000,000 shares authorized, 654,671,194 and 651,800,786 shares issued	0	0
Additional paid-in capital	11,641	11,526
Retained earnings	5,650	1,170
Accumulated other comprehensive loss	(5,845)	(5,801)
Treasury stock, at cost, 11,224,246 and 10,535,033 shares	(341)	(313)
Total stockholders' equity	11,105	6,582
Total liabilities and stockholders' equity	73,644	72,288
Air traffic
Current Liabilities:
Deferred revenue liability, current	7,044	8,160
Noncurrent Liabilities:
Loyalty program deferred revenue		100
Loyalty program
Current Liabilities:
Deferred revenue liability, current	3,908	3,434
Noncurrent Liabilities:
Loyalty program deferred revenue	$ 4,512	$ 4,448

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Current Assets:
Allowance for uncollectible accounts	$ 17	$ 23
Allowance for obsolescence	123	136
Noncurrent Assets:
Accumulated depreciation and amortization	21,707	20,370
Accumulated amortization	$ 911	$ 902
Stockholders' Equity:
Common stock, par value (USD per share)	$ 0.0001	$ 0.0001
Common stock, authorized (shares)	1,500,000,000	1,500,000,000
Common stock, issued (shares)	654,671,194	651,800,786
Treasury stock, at cost (shares)	11,224,246	10,535,033

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating Revenue:
Total operating revenue	$ 58,048	$ 50,582	$ 29,899
Operating Expense:
Salaries and related costs	14,607	11,902	9,728
Aircraft fuel and related taxes	11,069	11,482	5,633
Ancillary businesses and refinery	4,172	5,756	3,957
Contracted services	4,041	3,345	2,420
Landing fees and other rents	2,563	2,181	2,019
Aircraft maintenance materials and outside repairs	2,432	1,982	1,401
Depreciation and amortization	2,341	2,107	1,998
Passenger commissions and other selling expenses	2,334	1,891	953
Regional carrier expense	2,200	2,051	1,736
Passenger service	1,750	1,453	756
Profit sharing	1,383	563	108
Pilot agreement and related expenses	864	0	0
Aircraft rent	532	508	430
Government grant recognition	0	0	(4,512)
Other	2,239	1,700	1,386
Total operating expense	52,527	46,921	28,013
Operating Income	5,521	3,661	1,886
Non-Operating Income/(Expense):
Interest expense, net	(834)	(1,029)	(1,279)
Gain/(loss) on investments, net	1,263	(783)	56
Loss on extinguishment of debt	(63)	(100)	(319)
Pension and related (expense)/benefit	(244)	292	451
Miscellaneous, net	(35)	(127)	(397)
Total non-operating income/(expense), net	87	(1,747)	(1,488)
Income Before Income Taxes	5,608	1,914	398
Income Tax Provision	(999)	(596)	(118)
Net Income	$ 4,609	$ 1,318	$ 280
Basic Earnings Per Share (USD per share)	$ 7.21	$ 2.07	$ 0.44
Diluted Earnings Per Share (USD per share)	$ 7.17	$ 2.06	$ 0.44
Passenger
Operating Revenue:
Total operating revenue	$ 48,909	$ 40,218	$ 22,519
Cargo
Operating Revenue:
Total operating revenue	723	1,050	1,032
Other
Operating Revenue:
Total operating revenue	$ 8,416	$ 9,314	$ 6,348

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income/(Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net Income	$ 4,609	$ 1,318	$ 280
Other comprehensive income:
Net change in pension and other benefits	(44)	1,329	1,908
Total Other Comprehensive (Loss)/Income	(44)	1,329	1,908
Comprehensive Income	$ 4,565	$ 2,647	$ 2,188

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash Flows From Operating Activities:
Net income	$ 4,609	$ 1,318	$ 280
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	2,341	2,107	1,998
Deferred income taxes	980	591	115
(Gain)/loss on fair value investments	(1,283)	874	(38)
Pension, postretirement and postemployment payments greater than expense	(121)	(453)	(2,038)
Changes in certain assets and liabilities:
Receivables	(7)	(728)	(981)
Fuel inventory	121	(158)	(318)
Prepaids and other current assets	17	(867)	(58)
Profit sharing	821	455	108
Other payables, deferred revenue and accrued liabilities	(285)	1,226	1,986
Noncurrent liabilities	(18)	(348)	(399)
Other, net	(33)	120	419
Net cash provided by operating activities	6,464	6,363	3,264
Property and equipment additions:
Flight equipment, including advance payments	(3,645)	(4,495)	(1,596)
Ground property and equipment, including technology	(1,678)	(1,871)	(1,651)
Purchase of equity investments	(152)	(870)	0
Purchase of short-term investments	(2,312)	(2,704)	(12,655)
Redemption of short-term investments	4,547	2,804	15,036
Other, net	92	212	(32)
Net cash used in investing activities	(3,148)	(6,924)	(898)
Cash Flows From Financing Activities:
Proceeds from long-term obligations	878	0	1,902
Payments on debt and finance lease obligations	(4,071)	(4,475)	(5,834)
Cash dividends	(128)	0	0
Other, net	(73)	(60)	80
Net cash used in financing activities	(3,394)	(4,535)	(3,852)
Net Decrease in Cash, Cash Equivalents and Restricted Cash	(78)	(5,096)	(1,486)
Cash, cash equivalents and restricted cash at beginning of period	3,473	8,569	10,055
Cash, cash equivalents and restricted cash at end of period	3,395	3,473	8,569
Supplemental Disclosure of Cash Paid for Interest	1,164	1,261	1,524
Non-Cash Transactions:
Right-of-use assets acquired under operating leases	661	531	2,113
Flight and ground equipment acquired under finance leases	31	91	1,049
Operating leases converted to finance leases	84	342	42
Equity investments and other financings	0	330	0
Air traffic
Changes in certain assets and liabilities:
Liabilities and deferred revenue	(1,216)	1,902	1,814
Loyalty program
Changes in certain assets and liabilities:
Liabilities and deferred revenue	$ 538	$ 324	$ 376

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions		Total	Common Stock	Additional Paid-In Capital	Retained Earnings / (Accumulated Deficit)	Accumulated Other Comprehensive Loss	Treasury Stock
Beginning balance (in shares) at Dec. 31, 2020			647,000,000
Beginning balance at Dec. 31, 2020		$ 1,534	$ 0	$ 11,259	$ (428)	$ (9,038)	$ (259)
Beginning balance, treasury (in shares) at Dec. 31, 2020							9,000,000
Consolidated Statements of Stockholders' Equity
Net income		280			280
Other comprehensive income (loss)		1,908				1,908
Common stock issued for employee equity awards (shares)	[1]		3,000,000				1,000,000
Common stock issued for employee equity awards	[1]	79		102			$ (23)
Government grant warrant issuance		86		86
Ending balance (in shares) at Dec. 31, 2021			650,000,000
Ending balance at Dec. 31, 2021		3,887	$ 0	11,447	(148)	(7,130)	$ (282)
Ending balance, treasury (in shares) at Dec. 31, 2021							10,000,000
Consolidated Statements of Stockholders' Equity
Net income		1,318			1,318
Other comprehensive income (loss)		1,329				1,329
Common stock issued for employee equity awards (shares)	[1]		2,000,000				1,000,000
Common stock issued for employee equity awards	[1]	48		79			$ (31)
Ending balance (in shares) at Dec. 31, 2022			652,000,000
Ending balance at Dec. 31, 2022		$ 6,582	$ 0	11,526	1,170	(5,801)	$ (313)
Ending balance, treasury (in shares) at Dec. 31, 2022		10,535,033					11,000,000
Consolidated Statements of Stockholders' Equity
Net income		$ 4,609			4,609
Dividends declared ($0.20 per share)		(129)			(129)
Other comprehensive income (loss)		(44)				(44)
Common stock issued for employee equity awards (shares)	[1]		3,000,000
Common stock issued for employee equity awards	[1]	87		115			$ (28)
Ending balance (in shares) at Dec. 31, 2023			655,000,000
Ending balance at Dec. 31, 2023		$ 11,105	$ 0	$ 11,641	$ 5,650	$ (5,845)	$ (341)
Ending balance, treasury (in shares) at Dec. 31, 2023		11,224,246					11,000,000
[1] Treasury shares were withheld for payment of taxes, at a weighted average price per share of $40.08, $40.52 and $38.87 in 2023, 2022 and 2021, respectively.

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Stockholders' Equity [Abstract]
Cash dividends declared per share (USD per share)	$ 0.20
Treasury shares withheld for payment of taxes, weighted average price per share (USD per share)	$ 40.08	$ 40.52	$ 38.87

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation Delta Air Lines, Inc., a Delaware corporation, provides scheduled air transportation for passengers and cargo throughout the United States ("U.S.") and around the world. Our Consolidated Financial Statements include the accounts of Delta Air Lines, Inc. and our consolidated subsidiaries and have been prepared in accordance with generally accepted accounting principles in the U.S. ("GAAP"). We are not the primary beneficiary of, nor do we have a controlling financial interest in, any variable interest entity. Accordingly, we have not consolidated any variable interest entity. We have marketing alliances with other airlines to enhance our access to domestic and international markets. These arrangements may include codesharing, reciprocal loyalty program benefits, shared or reciprocal access to passenger lounges, joint promotions, common use of airport gates and ticket counters, office co-location and other marketing agreements. We have received antitrust immunity for certain marketing arrangements, which enables us to offer a more integrated route network and develop common sales, marketing and discount programs for customers. Some of our marketing arrangements provide for the sharing of revenues and expenses. Revenues and expenses associated with collaborative arrangements are presented on a gross basis in the applicable line items on our Consolidated Statements of Operations ("income statement"). We have reclassified certain prior period amounts to conform to the current period presentation. Unless otherwise noted, all amounts disclosed are stated before consideration of income taxes. Use of Estimates We are required to make estimates and assumptions when preparing our Consolidated Financial Statements in accordance with GAAP. These estimates and assumptions affect the amounts reported in our Consolidated Financial Statements and the accompanying notes. Actual results could differ materially from those estimates. Recent Accounting Standards Standards Effective in Future Years Fair Value of Equity Investments. In June 2022, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2022-03, "Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions." Under this standard, a contractual restriction on the sale of an equity security is not considered in measuring the security's fair value. The standard also requires certain disclosures for equity securities that are subject to contractual restrictions. The ASU becomes effective January 1, 2024, however we early adopted this standard as of December 31, 2023. The new standard does not impact the valuation of our equity investments, but we have included the newly required disclosures related to the contractual sale restrictions associated with our investment in Wheels Up Experience Inc. ("Wheels Up"). See Note 4, "Investments," for additional details. Segment Reporting. In November 2023, the FASB issued ASU No. 2023-07, "Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures." This standard requires disclosure of significant segment expenses and other segment items by reportable segment. This ASU becomes effective for annual periods beginning in 2024 and interim periods in 2025. We are assessing the impact of this ASU and upon adoption expect that any impact would be limited to additional segment expense disclosures in the footnotes to our Consolidated Financial Statements. Income Taxes. In December 2023, the FASB issued ASU No. 2023-09, "Income Taxes (Topic 740): Improvements to Income Tax Disclosures." This standard enhances disclosures related to income taxes, including the rate reconciliation and information on income taxes paid. This ASU becomes effective January 1, 2025. We are assessing the impact of this ASU and upon adoption may be required to include certain additional disclosures in the footnotes to our Consolidated Financial Statements. Significant Accounting Policies Our significant accounting policies are disclosed below or included within the topic-specific notes included herein. Cash and Cash Equivalents and Short-Term Investments Short-term, highly liquid investments with maturities of three months or less when purchased are classified as cash and cash equivalents. Investments with maturities of greater than three months, but not in excess of one year, when purchased are classified as short-term investments and are stated at fair value. Investments with maturities beyond one year when purchased may be classified as short-term investments if they are expected to be available to support our short-term liquidity needs. Our short-term investments in debt securities purchased prior to October 1, 2022 are classified as fair value investments under the fair value option and unrealized gains and losses are recorded in non-operating expense. Our short-term investments in debt securities purchased on or after October 1, 2022 are classified as available-for-sale investments and are stated at fair value with unrealized gains and losses recorded in accumulated other comprehensive income/(loss) ("AOCI"). Realized gains and losses on these investments are recorded in non-operating expense. The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the Consolidated Balance Sheets ("balance sheets") that sum to the total of the same such amounts shown within the Consolidated Statements of Cash Flows ("cash flows statement"). Reconciliation of cash, cash equivalents and restricted cash December 31, (in millions) 2023 2022 2021 Current assets: Cash and cash equivalents $ 2,741 $ 3,266 $ 7,933 Restricted cash included in prepaid expenses and other 199 138 163 Noncurrent assets: Restricted cash included in other noncurrent assets 455 69 473 Total cash, cash equivalents and restricted cash $ 3,395 $ 3,473 $ 8,569 Inventories Fuel. As part of our strategy to mitigate the cost of the refining margin reflected in the price of jet fuel, our wholly owned subsidiary, Monroe Energy, LLC ("Monroe"), operates the Trainer oil refinery. Refined products (finished goods) and feedstock and blendstock inventories (work-in-process) are both carried at the lower of cost and net realizable value. We use jet fuel in our airline operations that is produced by the refinery and procured through the exchanges with third parties of gasoline, diesel and other refined products ("non-jet fuel products") the refinery produces. Cost is determined using the first-in, first-out method. Costs include the raw material consumed plus direct manufacturing costs (such as labor, utilities and supplies) as incurred and an applicable portion of manufacturing overhead. Expendables Parts and Supplies. Inventories of expendable parts related to flight equipment, which cannot be economically repaired, reconditioned or reused after removal from the aircraft, are carried at moving average cost and charged to aircraft maintenance materials and outside repairs as consumed. An allowance for obsolescence is provided over the remaining useful life of the related fleet. We also provide allowances for parts identified as excess or obsolete to reduce the carrying costs to the lower of cost or net realizable value. These parts are estimated to have residual value of 5% of the original cost. Accounting for Refinery Related Buy/Sell Agreements To the extent that we receive jet fuel for non-jet fuel products exchanged under buy/sell agreements, we account for these transactions as nonmonetary exchanges. We have recorded these nonmonetary exchanges at the carrying amount of the non-jet fuel products transferred within aircraft fuel and related taxes on the income statement. Derivatives Changes in fuel prices, interest rates and foreign currency exchange rates impact our results of operations. In an effort to manage our exposure to these risks, we may enter into derivative contracts and adjust our derivative portfolio as market conditions change. Our derivative contracts are recognized at fair value on our balance sheets and had net balances of $5 million and $47 million at December 31, 2023 and 2022, respectively. See Note 3, "Fair Value Measurements," for further information regarding our derivative contracts. Long-Lived Assets Our long-lived lived assets include property and equipment, net and operating lease right-of-use ("ROU") assets on our balance sheets. See Note 7, "Leases," for further information regarding our leases. The following table summarizes our property and equipment: Property and equipment by classification December 31, (in millions, except for estimated useful life) Estimated Useful Life 2023 2022 Flight equipment (1) 25-34 years $ 40,976 $ 38,091 Ground property and equipment 3-40 years 9,986 8,996 Information technology-related assets 3-15 years 3,307 3,375 Flight and ground equipment under finance leases Shorter of lease term or estimated useful life 1,862 1,950 Advance payments for equipment 1,062 1,067 Less: accumulated depreciation and amortization (2) (21,707) (20,370) Total property and equipment, net $ 35,486 $ 33,109 (1) Includes aircraft and associated engines and parts. (2) Includes accumulated amortization for flight and ground equipment under finance leases in the amount of $525 million and $463 million at December 31, 2023 and 2022, respectively. We record property and equipment at cost and depreciate or amortize these assets on a straight-line basis to their estimated residual values over their estimated useful lives. The estimated useful life for leasehold improvements is the shorter of lease term or estimated useful life. Depreciation and amortization expense related to our property and equipment was $2.3 billion, $2.1 billion and $2.0 billion for the years ended December 31, 2023, 2022 and 2021, respectively. Residual values for owned aircraft, engines, spare parts and simulators are generally 5% to 10% of cost. We capitalize certain internal and external costs incurred to develop and implement software and amortize those costs over an estimated useful life of three Our tangible assets consist primarily of flight equipment, which is mobile across geographic markets. Accordingly, assets are not allocated to specific geographic regions. We review flight equipment, ROU assets and other long-lived assets used in operations for impairment losses when events and circumstances indicate the assets may be impaired. Factors which could be indicators of impairment include, but are not limited to (1) a decision to permanently remove flight equipment or other long-lived assets from operations, (2) significant changes in the estimated useful life, (3) significant changes in projected cash flows, (4) permanent and significant declines in fleet fair values and (5) changes to the regulatory environment. For long-lived assets held for sale, we discontinue depreciation and record impairment losses when the carrying amount of these assets is greater than the fair value less the cost to sell. To determine whether impairments exist for aircraft used in operations, we group assets at the fleet type level or at the contract level for aircraft operated by third-party regional carriers (i.e., the lowest level for which there are identifiable cash flows) and then estimate future cash flows based on projections of capacity, passenger mile yield, fuel and labor costs and other relevant factors. If an asset group is impaired, the impairment loss recognized is the amount by which the asset group's carrying amount exceeds its estimated fair value. We estimate aircraft fair values using published sources, appraisals and bids received from third parties, as available. Income Taxes We account for deferred income taxes under the liability method. We recognize deferred tax assets and liabilities based on the tax effects of temporary differences between the financial statement and tax basis of assets and liabilities, as measured by current enacted tax rates. Deferred tax assets and liabilities are net by jurisdiction and are recorded as noncurrent on the balance sheets. We have elected to recognize global intangible low tax income in the period it arises and do not recognize deferred taxes for basis differences that may reverse in future years. A valuation allowance is recorded to reduce deferred tax assets when necessary. We periodically assess whether it is more likely than not that we will generate sufficient taxable income to realize our deferred income tax assets. We establish valuation allowances if it is more likely than not that we will be unable to realize our deferred income tax assets. In making this determination, we consider available positive and negative evidence and make certain assumptions. We consider, among other things, projected future taxable income, scheduled reversals of deferred tax liabilities, the overall business environment, our historical financial results and tax planning strategies. See Note 11, "Income Taxes," for further information on our deferred income taxes. Fuel Card Obligation We have a purchasing card with American Express for the purpose of buying jet fuel and crude oil. The card carried a maximum credit limit of $1.1 billion as of December 31, 2023 and must be paid monthly. At both December 31, 2023 and 2022, we had $1.1 billion outstanding on this purchasing card and the activity was classified as a financing activity in our cash flows statement. Manufacturers' Credits We periodically receive credits in connection with the acquisition of aircraft and engines. These credits are deferred until the aircraft and engines are delivered, and then applied as a reduction to the cost of the related equipment. Maintenance Costs We record maintenance costs related to our mainline and regional fleets in aircraft maintenance materials and outside repairs and regional carrier expense, respectively. Maintenance costs are expensed as incurred, except for costs incurred under power-by-the-hour contracts, which are expensed based on actual hours flown. Power-by-the-hour contracts transfer certain risk to third-party service providers and fix the amount we pay per flight hour or per flight cycle to the service provider in exchange for maintenance and repairs under a predefined maintenance program. Modifications that enhance the operating performance or extend the useful lives of airframes or engines are capitalized and amortized over the remaining estimated useful life of the asset or the remaining lease term, whichever is shorter. Advertising Costs We expense advertising costs in passenger commissions and other selling expenses in the year the advertising first takes place. Advertising expense was $347 million, $302 million and $198 million for the years ended December 31, 2023, 2022 and 2021, respectively. Commissions and Merchant Fees Passenger sales commissions and merchant fees are recognized in passenger commissions and other selling expenses when the related revenue is recognized.

REVENUE RECOGNITION

REVENUE RECOGNITION	12 Months Ended
	Dec. 31, 2023
Revenue from Contract with Customer [Abstract]
REVENUE RECOGNITION	REVENUE RECOGNITION Passenger Revenue Passenger revenue is composed of passenger ticket sales, loyalty travel awards and travel-related services performed in conjunction with a passenger’s flight. Passenger revenue by category Year Ended December 31, (in millions) 2023 2022 2021 Ticket $ 43,596 $ 35,626 $ 19,339 Loyalty travel awards 3,462 2,898 1,786 Travel-related services 1,851 1,694 1,394 Total passenger revenue $ 48,909 $ 40,218 $ 22,519 Ticket Passenger Tickets. We defer sales of passenger tickets to be flown by us or that we sell on behalf of other airlines in our air traffic liability. Passenger revenue is recognized when we provide transportation. For tickets that we sell on behalf of other airlines, we reduce the air traffic liability when consideration is remitted to those airlines. The air traffic liability primarily includes sales of passenger tickets with scheduled departure dates in the future and travel credits, which can be applied as payment toward the cost of a ticket. We periodically evaluate the estimated air traffic liability and may record adjustments in our income statement. These adjustments relate primarily to tickets that expire unused ("ticket breakage"), refunds, exchanges, transactions with other airlines and other items for which final settlement occurs in periods subsequent to the sale of the related tickets at amounts other than the original sales price. We recognized approximately $7.4 billion, $4.2 billion and $2.2 billion in passenger revenue during the years ended December 31, 2023, 2022 and 2021, respectively, that had been recorded in our air traffic liability balance at the beginning of those periods. As of December 31, 2023, all of our air traffic liability was recorded as a current liability. As of December 31, 2022, our air traffic liability was $8.3 billion, of which $100 million was included in other noncurrent liabilities on our balance sheet due to ticket validity extensions related to certain tickets and travel credits as of the end of 2022. Ticket Breakage. We estimate the value of ticket breakage and recognize revenue at the scheduled flight date. Our ticket breakage estimates are primarily based on historical experience, ticket contract terms and customers’ travel behavior. Regional Carriers. Our regional carriers include both third-party regional carriers with which we have contract carrier agreements ("contract carriers") and Endeavor Air, Inc., our wholly owned subsidiary. Our contract carrier agreements are primarily structured as capacity purchase agreements where we purchase all or a portion of the contract carrier's capacity and are responsible for selling the seat inventory we purchase. We record revenue related to our capacity purchase agreements in passenger revenue and the related expenses in regional carrier expense. See Note 10, "Commitments and Contingencies," for additional information regarding contract carrier agreements. Loyalty Travel Awards Loyalty travel awards revenue is related to the redemption of mileage credits ("miles") for travel. We recognize loyalty travel awards revenue in passenger revenue as miles are redeemed and transportation is provided. See below for discussion of our loyalty program accounting policies. Travel-Related Services Travel-related services are primarily composed of services performed in conjunction with a passenger’s flight, including baggage fees, administrative fees, and on-board sales. We recognize revenue for these services when the related transportation service is provided. Loyalty Program Our SkyMiles loyalty program generates customer loyalty by rewarding customers with incentives to travel on Delta. This program allows customers to earn miles by flying on Delta, Delta Connection carriers and other airlines that participate in the loyalty program. When traveling, customers earn miles primarily based on the passenger's loyalty program status, fare class and ticket price. Customers can also earn miles through participating companies. Miles are redeemable by customers in future periods for air travel on Delta and other participating airlines, access to Delta Sky Club and other program awards. To facilitate transactions with participating companies, we sell miles to non-airline businesses and other airlines. The loyalty program includes two types of transactions that are considered revenue arrangements with multiple performance obligations (1) passenger ticket sales earning miles and (2) sale of miles to participating companies. Passenger Ticket Sales Earning Miles. Passenger ticket sales earning miles provide customers with (1) miles earned and (2) air transportation, which are each considered performance obligations. We value each performance obligation on a standalone basis. To value the miles earned, we consider the quantitative value a passenger receives by redeeming miles for a ticket rather than paying cash, which is referred to as equivalent ticket value ("ETV"). Our estimate of ETV is adjusted for miles that are not likely to be redeemed ("mileage breakage"). We use statistical models to estimate mileage breakage based on historical redemption patterns. A change in assumptions regarding the redemption activity for miles or the estimated fair value of miles expected to be redeemed could have a material impact on our revenue in the year in which the change occurs and in future years. We recognize mileage breakage proportionally during the period in which the remaining miles are actually redeemed. We defer revenue for the miles when earned and recognize loyalty travel awards in passenger revenue as the miles are redeemed and transportation is provided. We record the air transportation portion of the passenger ticket sales in air traffic liability and recognize passenger revenue when we provide transportation or if the ticket goes unused. Sale of Miles to Participating Companies. Customers earn miles based on their spending with participating companies, such as credit card, retail, ridesharing, car rental and hotel companies, with which we have marketing agreements to sell miles. Our contracts to sell miles under these marketing agreements have multiple performance obligations. Payments are typically due to us monthly based on the volume of miles sold during the period, and the initial terms of our marketing contracts are from one Our most significant contract to sell miles relates to our co-brand credit card relationship with American Express. Our agreements with American Express provide for joint marketing, grant certain benefits to Delta-American Express co-branded credit card holders ("cardholders") and American Express Membership Rewards program participants, and allow American Express to market its services or products using our customer database. Cardholders earn miles for making purchases using co-branded cards, and certain cardholders may also check their first bag for free, are granted discounted access to Delta Sky Club lounges and receive priority boarding and other benefits while traveling on Delta. Additionally, participants in the American Express Membership Rewards program may exchange their points for miles under the loyalty program. We sell miles at agreed-upon rates to American Express which are then provided to their customers under the co-brand credit card program and the Membership Rewards program. We account for marketing agreements, including those with American Express, by allocating the consideration to the individual products and services delivered. We allocate the value based on the relative selling prices of those products and services, which generally consist of award travel, priority boarding, baggage fee waivers, lounge access and the use of our brand. We determine our best estimate of the selling prices by using a discounted cash flow analysis using multiple inputs and assumptions, including (1) the expected number of miles awarded and number of miles redeemed, (2) ETV for the award travel obligation adjusted for mileage breakage, (3) published rates on our website for baggage fees, discounted access to Delta Sky Club lounges and other benefits while traveling on Delta, (4) brand value (using estimated royalties generated from the use of our brand) and (5) volume discounts provided to certain partners. We defer the amount allocated to award travel as part of loyalty program deferred revenue and recognize loyalty travel awards in passenger revenue as the miles are redeemed and transportation is provided. Revenue allocated to services performed in conjunction with a passenger’s flight, such as baggage fee waivers, is recognized as travel-related services in passenger revenue when the related service is performed. Revenue allocated to Delta Sky Club lounge access is recognized as miscellaneous in other revenue as access is provided. Revenue allocated to the remaining performance obligations, primarily brand value, is recorded as loyalty program in other revenue as miles are delivered. Current Activity of the Loyalty Program. Miles are combined in one homogeneous pool and are not separately identifiable. Therefore, the revenue is comprised of miles that were part of the loyalty program deferred revenue balance at the beginning of the period as well as miles that were issued during the period. The table below presents the activity of the current and noncurrent loyalty program deferred revenue, and includes miles earned through travel and miles sold to participating companies, which are primarily through marketing agreements. Loyalty program activity (in millions) 2023 2022 2021 Balance at January 1 $ 7,882 $ 7,559 $ 7,182 Miles earned 4,173 3,419 2,238 Travel miles redeemed (3,462) (2,898) (1,786) Non-travel miles redeemed (173) (198) (75) Balance at December 31 $ 8,420 $ 7,882 $ 7,559 The timing of mile redemptions can vary widely; however, the majority of new miles have historically been redeemed within two years of being earned. The loyalty program deferred revenue classified as a current liability represents our estimate of revenue expected to be recognized in the next twelve months based on projected redemptions, while the balance classified as a noncurrent liability represents our estimate of revenue expected to be recognized beyond twelve months. Cargo Revenue Cargo revenue is recognized when we provide the transportation. Other Revenue Year Ended December 31, (in millions) 2023 2022 2021 Refinery $ 3,379 $ 4,977 $ 3,229 Loyalty program 3,093 2,597 1,770 Ancillary businesses 840 846 793 Miscellaneous 1,104 894 556 Total other revenue $ 8,416 $ 9,314 $ 6,348 Refinery. This represents refinery sales to third parties. See Note 14, "Segments," for more information on revenue recognition within our refinery segment. Loyalty Program. This relates to revenues from brand usage by third parties and other performance obligations embedded in miles sold, which are included within the total cash sales from marketing agreements, discussed above. This also includes the redemption of miles for non-travel awards. Ancillary Businesses. This includes aircraft maintenance services we provide to third parties and our vacation wholesale operations. Miscellaneous. This is primarily composed of lounge access, including access provided to certain American Express cardholders, and codeshare revenues. Revenue by Geographic Region Operating revenue for the airline segment is recognized in a specific geographic region based on the origin, flight path and destination of each flight segment. A significant portion of the refinery segment's revenues typically consists of fuel sales to support the airline, which is eliminated in the Consolidated Financial Statements. The remaining operating revenue for the refinery segment is included in the domestic region. Our passenger and operating revenue by geographic region are summarized in the following table: Revenue by geographic region Passenger Revenue Operating Revenue Year Ended December 31, Year Ended December 31, (in millions) 2023 2022 2021 2023 2022 2021 Domestic $ 33,968 $ 30,197 $ 18,468 $ 40,845 $ 38,478 $ 24,320 Atlantic 9,057 6,093 1,777 10,458 7,429 2,537 Latin America 3,798 2,889 1,873 4,292 3,334 2,284 Pacific 2,086 1,039 401 2,453 1,341 758 Total $ 48,909 $ 40,218 $ 22,519 $ 58,048 $ 50,582 $ 29,899 Accounts Receivable Accounts receivable primarily consist of amounts due from credit card companies from the sale of passenger tickets, ancillary businesses, refinery sales and other companies for the purchase of miles under the loyalty program. We provide an allowance for uncollectible accounts using an expected credit loss model which represents our estimate of expected credit losses over the lifetime of the asset. Passenger Taxes and Fees We are required to charge certain taxes and fees on our passenger tickets, including U.S. federal transportation taxes, federal security charges, airport passenger facility charges and foreign arrival and departure taxes. These taxes and fees are assessments on the customer for which we act as a collection agent and these amounts are not included in passenger revenue. We record a liability when the amounts are collected and reduce the liability when payments are made to the applicable government agency or operating carrier (i.e., for codeshare-related fees).

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Fair value is a market-based measurement that is determined based on assumptions that market participants would use in pricing an asset or liability. Each fair value measurement is classified into one of the following levels based on the information used in the valuation: • Level 1. Observable inputs such as quoted prices in active markets. • Level 2. Inputs, other than quoted prices in active markets, that are observable either directly or indirectly. • Level 3. Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. Assets and liabilities measured at fair value are based on the valuation techniques identified in the tables below. The valuation techniques are as follows: (a) Market Approach. Prices and other relevant information generated by observable transactions involving identical or comparable assets or liabilities. (b) Income Approach. Techniques to convert future amounts to a single present value amount based on market expectations (including present value techniques and option-pricing models). Assets (Liabilities) Measured at Fair Value on a Recurring Basis (1) December 31, 2023 Valuation Technique (in millions) Total Level 1 Level 2 Level 3 Cash equivalents $ 1,545 $ 1,545 $ — $ — (a) Restricted cash equivalents 653 653 — — (a) Short-term investments U.S. Government securities 859 204 655 — (a) Corporate obligations 218 — 218 — (a) Other fixed income securities 50 — 50 — (a) Long-term investments and related 2,867 2,614 134 119 (a)(b) Hedge derivatives, net Fuel hedge contracts 5 — 5 — (a)(b) December 31, 2022 Valuation Technique (in millions) Total Level 1 Level 2 Level 3 Cash equivalents $ 2,021 $ 2,021 $ — $ — (a) Restricted cash equivalents 206 206 — — (a) Short-term investments U.S. Government securities 1,587 122 1,465 — (a) Corporate obligations 1,614 — 1,614 — (a) Other fixed income securities 67 — 67 — (a) Long-term investments 1,450 1,305 38 107 (a)(b) Hedge derivatives, net Fuel hedge contracts (47) — (47) — (a)(b) (1) See Note 9, "Employee Benefit Plans," for fair value of benefit plan assets. Cash Equivalents and Restricted Cash Equivalents. Cash equivalents generally consist of money market funds. Restricted cash equivalents are recorded in prepaid expenses and other and other noncurrent assets on our balance sheets and generally consist of money market funds, time deposits, commercial paper and negotiable certificates of deposit, which primarily relate to proceeds from debt issued to finance, among other things, a portion of the construction costs for our new terminal facilities at New York's LaGuardia Airport as well as certain self-insurance obligations and airport commitments. The fair value of these cash equivalents is based on a market approach using prices generated by market transactions involving identical or comparable assets. Short-Term Investments. The fair values of our short-term investments are based on a market approach using industry standard valuation techniques that incorporate observable inputs such as quoted market prices, interest rates, benchmark curves, credit ratings of the security and other observable information. As of December 31, 2023, the estimated fair value of our short-term investments was $1.1 billion. These investments are expected to mature in one year or less. Long-Term Investments and Related. Our long-term investments measured at fair value primarily consist of equity investments, which are valued based on market prices or other observable transactions and inputs, and are recorded in equity investments on our balance sheets. Our equity investments in private companies are classified as Level 3 in the fair value hierarchy as their equity is not traded on a public exchange and our valuations incorporate certain unobservable inputs, including non-public equity issuances. As of December 31, 2023 and December 31, 2022, our equity investment in Wheels Up was classified as Level 1 in the fair value hierarchy. In the September 2023 quarter, our Wheels Up investment was classified as Level 3 after we determined the quoted price of its publicly-traded shares did not represent fair value due to the short time between closing of Wheels Up's credit facility and our quarterly reporting date. Given the amount of time that elapsed by December 31, 2023, we returned to valuing our equity investment in Wheels Up using the closing price of its shares at year end as traded on the New York Stock Exchange. Fair value measurement using unobservable inputs is inherently uncertain, and a change in significant inputs could result in different fair values. During the year ended December 31, 2023 there were no material gains or losses related to investments classified as Level 3 as a result of fair value adjustments. See Note 4, "Investments," for further information on our long-term investments. Hedge Derivatives. A portion of our derivative contracts may be negotiated over-the-counter with counterparties without going through a public exchange. Accordingly, our fair value assessments give consideration to the risk of counterparty default (as well as our own credit risk). Such contracts would be classified as Level 2 within the fair value hierarchy. The remainder of our hedge contracts may be comprised of futures contracts, which are traded on a public exchange. These contracts would be classified within Level 1 of the fair value hierarchy. • Fuel Hedge Contracts. Our derivative contracts to hedge the financial risk from changing fuel prices are related to Monroe’s inventory. Our fuel hedge portfolio may consist of a combination of options, swaps or futures. Option and swap contracts are valued under income approaches using option pricing models and discounted cash flow models, respectively, based on data either readily observable in public markets, derived from public markets or provided by counterparties who regularly trade in public markets. Futures contracts and options on futures contracts are traded on a public exchange and valued based on quoted market prices. We recognized losses of $6 million, $394 million and $146 million on our fuel hedge contracts in aircraft fuel and related taxes on our income statement for the years ended December 31, 2023, 2022 and 2021, respectively. The losses recognized during 2023 were composed of $58 million of settlements on contracts and $52 million of mark-to-market adjustments. Expense from the settlement of closed contracts is offset by higher operating profits at Monroe from higher pricing. See Note 14, "Segments," for further information on our Monroe refinery segment.

INVESTMENTS

INVESTMENTS	12 Months Ended
	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
INVESTMENTS	INVESTMENTS We have developed strategic relationships with a number of airlines and airline services companies through joint ventures and other forms of cooperation and support, including equity investments. Our equity investments reinforce our commitment to these relationships and generally enhance our ability to offer input to the investee on strategic issues and direction, in some cases through representation on the board of directors of the investee. Fair Value Investments. Changes in the valuation of investments accounted for at fair value are recorded in gain/(loss) on investments, net in our income statement within non-operating expense and are driven by changes in stock prices, foreign currency fluctuations and other valuation techniques for investments in companies without publicly-traded shares. Equity Method Investments. We record our share of our equity method investees' financial results in our income statement as described in the table below. Equity investments ownership interest and carrying value Accounting Treatment Ownership Interest Carrying Value (in millions) December 31, 2023 December 31, 2022 December 31, 2023 December 31, 2022 Air France-KLM Fair Value 3 % 3 % $ 110 $ 97 China Eastern Fair Value 2 % 2 % 134 189 CLEAR Fair Value 6 % 5 % 171 227 Grupo Aeroméxico Equity Method (1) 20 % 20 % 421 412 Hanjin-KAL Fair Value (2) 15 % 15 % 561 296 LATAM Fair Value 10 % 10 % 658 403 Unifi Aviation Equity Method (3) 49 % 49 % 162 165 Wheels Up Fair Value (4) 38 % 21 % 903 54 Other investments Various 337 285 Equity investments $ 3,457 $ 2,128 (1) Results are included in miscellaneous, net in our income statement under non-operating expense. (2) At December 31, 2023, we held 14.8% of the outstanding shares (including common and preferred), and 14.9% of the common shares, of Hanjin KAL. (3) Results are included in contracted services in our income statement as this entity is integral to the operations of our business by providing services at many of our airport locations. (4) See below for additional information about our ownership interest and voting rights. Wheels Up. During 2023, we announced an expanded strategic partnership with Wheels Up, which included an agreement for a new credit facility to Wheels Up. This new credit facility is comprised of a $390 million term loan, of which we contributed $150 million and several other lenders contributed the remaining $240 million, and a $100 million liquidity facility that we made available to Wheels Up in the event the company's liquidity falls below $100 million. In connection with the credit facility, the term loan investors received newly issued shares of Wheels Up's common stock representing 95% of Wheels Up's outstanding equity on a fully diluted basis as of the closing of the initial extension of credit. Our $150 million cash contribution was reflected as an investing outflow in our cash flows statement and allocated on a relative fair value basis to a loan receivable within other noncurrent assets and an equity investment on our balance sheet. Combined with our previous ownership stake, this new investment provides us with a 38% equity interest in Wheels Up. Delta's voting rights with respect to its Wheels Up equity interest are capped at 29.9%. As a result of the transaction, we concluded that Wheels Up is a variable interest entity ("VIE"). A VIE requires consolidation by the entity’s primary beneficiary. We determined that we are not the primary beneficiary after assessing the decision-making process for the significant activities of Wheels Up, concluding that Wheels Up's Board of Directors continues to possess the decision-making authority over the significant activities, and we do not control Wheels Up's Board. Based on this assessment, Wheels Up is not consolidated in our financial statements. We continue to account for our Wheels Up equity interest under the fair value option, as originally elected as part of our initial acquisition of Wheels Up shares in 2020. During 2023, we recorded a $786 million mark-to-market gain on our investment in Wheels Up based on the closing price of its shares as traded on the New York Stock Exchange. As of December 31, 2023, Wheels Up's public float was under 5% of the total outstanding shares which contributed to significant volatility in the value of our Wheels Up equity investment since the announcement of Wheels Up's credit facility in September 2023. The Wheels Up shares issued to Delta and the other term loan lenders were unregistered as of December 31, 2023 and are subject to a contractual transfer restriction until the first anniversary of the credit facility (September 2024). Following the expiration of this restriction, our equity investment in Wheels Up will be subject to certain, more limited transfer restrictions. We also account for our loan receivable at fair value, as the fair value option is applied to all of an investor's financial interests in the same entity. None of the $100 million liquidity facility has been drawn as of December 31, 2023. Other Investments This category includes various investments that are accounted for at fair value or under the equity method, depending on our ownership interest and the level of influence conveyed by our investment. Among others, this category includes our equity method investments in Virgin Atlantic and JFK IAT Member LLC. Virgin Atlantic. The carrying value of our investment in Virgin Atlantic remains zero as of December 31, 2023. We maintain our 49% equity interest and continue to track our share of Virgin Atlantic's losses under the equity method of accounting. These previously unrecognized losses are only recorded to the extent we make additional investments in Virgin Atlantic (i.e., additional shareholder support). As of December 31, 2023, we have approximately $400 million of unrecognized equity method losses related to our 49% interest in Virgin Atlantic. JFK IAT Member LLC is discussed further in Note 8, "Airport Redevelopment."

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND INTANGIBLE ASSETS	GOODWILL AND INTANGIBLE ASSETS Goodwill and Indefinite-Lived Intangible Assets Our goodwill and identifiable intangible assets relate to the airline segment. We apply a fair value-based impairment test to the carrying value of goodwill and indefinite-lived intangible assets on an annual basis (as of October 1) and, if certain events or circumstances indicate that an impairment loss may have been incurred, on an interim basis. We assess the value of our goodwill and indefinite-lived assets under either a qualitative or quantitative approach. Under a qualitative approach, we consider various market factors, including certain of the key assumptions listed below. We analyze these factors to determine if events and circumstances have affected the fair value of goodwill and indefinite-lived intangible assets. If we determine that it is more likely than not that the asset may be impaired, we use the quantitative approach to assess the asset's fair value and the amount of the impairment. Under a quantitative approach, we calculate the fair value of the asset incorporating the key assumptions listed below into our calculation. We value goodwill and indefinite-lived intangible assets primarily using market and income approach valuation techniques. These measurements include the following key assumptions (1) forecasted revenues, expenses and cash flows, (2) current discount rates, (3) observable market transactions and (4) anticipated changes to the regulatory environment (e.g., changes in slot access and/or availability, additional Open Skies agreements or changes to antitrust approvals). These assumptions are consistent with those that hypothetical market participants would use. Because we are required to make estimates and assumptions when evaluating goodwill and indefinite-lived intangible assets for impairment, actual transaction amounts may differ materially from these estimates. We recognize an impairment charge if the asset's carrying value exceeds its estimated fair value. Changes in certain events and circumstances could result in impairment or a change from indefinite-lived to definite-lived. Factors which could cause impairment include, but are not limited to (1) negative trends in our market capitalization, (2) reduced profitability resulting from lower passenger mile yields or higher input costs (primarily related to fuel and employees), (3) lower passenger demand as a result of weakened U.S. and global economies or other factors, (4) interruption to our operations due to a prolonged employee strike, terrorist attack or other reasons, (5) changes to the regulatory environment (e.g., changes in slot access and/or availability, additional Open Skies agreements or changes to antitrust approvals), (6) competitive changes by other airlines and (7) strategic changes to our operations leading to diminished utilization of the intangible assets. Identifiable Intangible Assets. Indefinite-lived assets are not amortized and consist of routes, slots, the Delta tradename and assets related to alliances and collaborative arrangements. Definite-lived intangible assets consist primarily of marketing and maintenance service agreements and are amortized on a straight-line basis or under the undiscounted cash flows method over the estimated economic life of the respective agreements. Costs incurred to renew or extend the term of an intangible asset are expensed as incurred. During the December 2023 quarter, we performed a quantitative valuation of our goodwill and indefinite-lived intangible assets as the most recent quantitative analysis was several years ago. These quantitative impairment tests of goodwill and intangibles concluded that there was no indication of impairment as the fair values exceeded our carrying values. Goodwill and indefinite-lived intangible assets by category Carrying Value at Excess Fair Value at 2023 Testing Date (in millions) December 31, 2023 December 31, 2022 Goodwill $ 9,753 $ 9,753 >100% International routes and slots 2,583 2,583 20% to >100% Airline alliances 1,863 1,863 30% to >100% Delta tradename 850 850 >100% Domestic slots 622 622 60% to >100% Total $ 15,671 $ 15,671 International Routes and Slots. This primarily relates to Pacific route authorities and slots at capacity-constrained airports in Asia, and slots at London-Heathrow airport. Airline Alliances. This primarily relates to our commercial agreements with LATAM and our SkyTeam partners. Domestic Slots. This primarily relates to our slots at New York-LaGuardia and Washington-Reagan National airports. Definite-Lived Intangible Assets Definite-lived intangible assets by category December 31, 2023 December 31, 2022 (in millions) Gross Carrying Value Gross Carrying Value Accumulated Amortization Marketing agreements $ 730 $ (708) $ 730 $ (704) Maintenance contracts 192 (150) 192 (145) Other 54 (53) 54 (53) Total $ 976 $ (911) $ 976 $ (902) Amortization expense was $9 million, $9 million and $10 million for the years ended December 31, 2023, 2022 and 2021, respectively. Based on our definite-lived intangible assets at December 31, 2023, we estimate that we will incur approximately $8 million of amortization expense annually from 2024 through 2028.

DEBT

DEBT	12 Months Ended
	Dec. 31, 2023
Debt Disclosure [Abstract]
DEBT	DEBT The following table summarizes our debt as of the dates indicated below: Summary of outstanding debt by category Maturity Dates Interest Rate(s) Per Annum at December 31, 2023 December 31, (in millions) 2023 2022 Unsecured Payroll Support Program Loans 2030 to 2031 1.00% $ 3,496 $ 3,496 Unsecured notes 2024 to 2029 2.90% to 7.38% 2,590 2,997 Financing arrangements secured by SkyMiles assets: SkyMiles Notes (1) 2024 to 2028 4.50% and 4.75% 4,518 5,144 SkyMiles Term Loan (1)(2) 2024 to 2027 9.17% 1,772 2,820 NYTDC Special Facilities Revenue Bonds (1) 2024 to 2045 4.00% to 6.00% 3,656 2,838 Financing arrangements secured by aircraft: Certificates (1) 2024 to 2028 2.00% to 8.00% 1,591 1,802 Notes (1)(2) 2024 to 2033 6.72% to 7.65% 165 813 Financing arrangements secured by slots, gates and/or routes: 2020 Senior Secured Notes 2025 7.00% 838 1,542 2018 Revolving Credit Facility (2) 2026 to 2028 Undrawn — — Other financings (1)(2) 2024 to 2030 2.51% to 5.00% 67 67 Other revolving credit facilities (2) 2024 to 2026 Undrawn — — Total secured and unsecured debt 18,693 21,519 Unamortized (discount)/premium and debt issuance cost, net and other (83) (138) Total debt 18,610 21,381 Less: current maturities (2,625) (2,055) Total long-term debt $ 15,985 $ 19,326 (1) Due in installments. (2) Certain financings are comprised of variable rate debt. All variable rates are equal to SOFR (generally subject to a floor) or another index rate plus a specified margin. Early Settlement of Outstanding Notes During 2023, we repurchased a principal amount of $1.4 billion of various secured and unsecured notes and a portion of the SkyMiles Term Loan on the open market and made early principal repayments of $585 million on various notes secured by aircraft. Collectively, these payments resulted in a $63 million loss on extinguishment of debt, which is recorded in non-operating expense in our income statement. Availability Under Revolving Facilities As of December 31, 2023, we had approximately $2.9 billion undrawn and available under our revolving credit facilities. In addition, we had $450 million of outstanding letters of credit as of December 31, 2023 that did not affect the availability under our revolvers. New York Transportation Development Corporation ("NYTDC") Special Facilities Revenue Bonds, Series 2023 In the December 2023 quarter, the NYTDC issued Special Facilities Revenue Bonds ("Series 2023 Bonds") in the aggregate principal amount of $878 million. We entered into loan agreements with the NYTDC to use the proceeds from the Series 2023 Bonds to finance a portion of the costs of the construction project that is currently in process at LaGuardia Airport. The proceeds from the Series 2023 Bonds are recorded in other noncurrent assets on our balance sheets. See Note 8, "Airport Redevelopment," for further information on our LaGuardia Airport project. We are required to pay debt service on the Series 2023 Bonds through payments under loan agreements with NYTDC, and we have guaranteed the Series 2023 Bonds. 2018 Revolving Credit Facility In the December 2023 quarter, we entered into an amended and restated credit agreement (the "A&R Credit Facility") which amends and restates the previous 2018 revolving credit facility. The A&R Credit Facility was undrawn at the time we entered into it and at December 31, 2023. The A&R Credit Facility contains a $1.325 billion three-year revolving facility, a $1.325 billion five-year revolving facility and a $360 million three-year standby letter of credit facility. Up to $250 million of each of the three-year and the five-year facilities can also be used for the issuance of letters of credit. The A&R Credit Facility contains an accordion feature under which the aggregate commitments can be increased up to $3.65 billion subject to certain conditions. The A&R Credit Facility is secured by a first lien on collateral consistent with the existing credit agreement, which includes our Pacific route authorities and certain related assets. We also have the option of pledging additional collateral. The A&R Credit Facility provides for the release of the lien on the collateral if we receive and maintain an investment grade rating with stable outlook from at least two of the three rating agencies (such date on which the collateral release conditions are met, the "Collateral Release Date"). Fair Value of Debt Market risk associated with our fixed- and variable-rate debt relates to the potential reduction in fair value and negative impact to future earnings, respectively, from an increase in interest rates. The fair value of debt, shown below, is principally based on reported market values, recently completed market transactions and estimates based on interest rates, maturities, credit risk and underlying collateral. Debt is primarily classified as Level 2 within the fair value hierarchy. Fair value of outstanding debt (in millions) December 31, December 31, Net carrying amount $ 18,610 $ 21,381 Fair value $ 18,400 $ 20,700 Covenants Our debt agreements contain various affirmative, negative and financial covenants. For example, our credit facilities and our SkyMiles financing agreements, contain, among other things, a minimum liquidity covenant. The minimum liquidity covenant requires us to maintain at least $2.0 billion of liquidity (defined as cash, cash equivalents, short-term investments and aggregate principal amount committed and available to be drawn under our revolving credit facilities). Certain of our debt agreements also include collateral coverage ratios and limit our ability to (1) incur liens under certain circumstances, (2) dispose of collateral and (3) engage in mergers and consolidations or transfer all or substantially all of our assets. On or after the Collateral Release Date, collateral and liquidity covenants in the A&R Credit Facility will be replaced to include, among other things, (1) restrictions on our ability to place liens on, or to sell or otherwise dispose of, a designated pool of assets and (2) minimum fixed charge coverage ratio and minimum asset coverage ratio covenants. Our SkyMiles financing agreements include a debt service coverage ratio and also restrict our ability to, among other things, (1) modify the terms of the SkyMiles program, or otherwise change the policies and procedures of the SkyMiles program, in a manner that would reasonably be expected to materially impair repayment of the SkyMiles Debt, (2) sell pre-paid miles in excess of $550 million in the aggregate and (3) terminate or materially modify the intercompany arrangements governing the relationship between Delta and SkyMiles IP Ltd. with respect to the SkyMiles program. Each of these restrictions, however, is subject to certain exceptions and qualifications that are set forth in these debt agreements. We were in compliance with the covenants in our debt agreements at December 31, 2023. Future Maturities The following table summarizes scheduled maturities of our debt for the years succeeding December 31, 2023: Future debt maturities (in millions) Total Debt Amortization of 2024 $ 2,633 $ (49) 2025 2,006 (32) 2026 2,610 (6) 2027 2,315 — 2028 1,884 — Thereafter 7,245 4 Total $ 18,693 $ (83) $ 18,610

LEASES

LEASES	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
LEASES	LEASES We lease property and equipment under finance and operating leases. For leases with terms greater than 12 months, we record the related asset and obligation at the present value of the fixed minimum lease payments over the term. Many of our leases include rental escalation clauses, renewal options and/or termination options that are factored into our determination of lease payments when appropriate. We do not separate lease and nonlease components of contracts, except for regional aircraft and information technology ("IT") assets as discussed below. We use the rate implicit in the lease to discount lease payments to present value, when readily determinable. As the rate implicit in the lease is rarely readily determinable, we use our incremental borrowing rate, which is based on the estimated interest rate for collateralized borrowing over a similar term of the lease at commencement date. Some of our aircraft lease agreements include provisions for residual value guarantees. These guarantees represent an immaterial portion of our lease liability. Aircraft As of December 31, 2023, including aircraft operated by our regional carriers, we leased 225 aircraft, of which 111 were under finance leases and 114 were operating leases. Our aircraft leases had remaining lease terms of five months to 12 years. In addition, we have regional aircraft leases that are embedded within our capacity purchase agreements and included in the ROU asset and lease liability. We allocated the consideration in each capacity purchase agreement to the lease and nonlease components based on their relative standalone fair values. Lease components of these agreements consist of 116 aircraft as of December 31, 2023 and nonlease components primarily consist of flight operations, in-flight and maintenance services. We determined our best estimate of the standalone fair value of the individual components by considering observable information including rates paid by our wholly owned subsidiary, Endeavor Air, Inc., and rates published by independent valuation firms. See Note 10, "Commitments and Contingencies," for additional information about our capacity purchase agreements. Airport Facilities Our facility leases are primarily for space at approximately 300 airports around the world that we serve. These leases reflect our use of airport terminals, office space, cargo warehouses and maintenance facilities. We generally lease space from government agencies that control the use of the airport, and as a result, these leases are classified as operating leases. The remaining lease terms vary from one month to 29 years. At the majority of the U.S. airports, the lease rates depend on airport operating costs or use of the facilities and are reset at least annually. Because of the variable nature of the rates, these leases are not recorded on our balance sheets as a ROU asset and lease liability. Some airport facilities have fixed payment schedules, the most significant of which are New York-LaGuardia and New York-JFK. For those airport leases, we have recorded a ROU asset and lease liability representing the fixed component of the lease payments. See Note 8, "Airport Redevelopment," for more information on our significant airport redevelopment projects. Other Ground Property and Equipment We lease certain IT assets (including servers, mainframes, etc.), ground support equipment (including tugs, tractors, fuel trucks and de-icers), and various other equipment. The remaining lease terms range from one month to six years. Certain leased assets are embedded within various ground and IT service agreements. For ground service contracts, we have elected to include both the lease and nonlease components in the lease asset and lease liability balances on our balance sheets. For IT service contracts, we have elected to separate the lease and nonlease components and only the lease components are included in the lease asset and lease liability balances on our balance sheets. The amounts of these lease and nonlease components are not significant. Lease Position The table below presents the lease-related assets and liabilities recorded on the balance sheets. Lease asset and liability balance sheet position by category December 31, (in millions) Classification on the Balance Sheet 2023 2022 Assets Operating lease assets Operating lease right-of-use assets $ 7,004 $ 7,036 Finance lease assets Property and equipment, net 1,338 1,487 Total lease assets $ 8,342 $ 8,523 Liabilities Current Operating Current maturities of operating leases $ 759 $ 714 Finance Current maturities of debt and finance leases 358 304 Noncurrent Operating Noncurrent operating leases 6,468 6,866 Finance Debt and finance leases 1,086 1,345 Total lease liabilities $ 8,671 $ 9,229 Weighted-average remaining lease term Operating leases 13 years 13 years Finance leases 4 years 5 years Weighted-average discount rate Operating leases 3.73 % 4.30 % Finance leases 3.12 % 3.05 % Lease Costs The table below presents certain information related to the lease costs for finance and operating leases. Lease cost by category Year Ended December 31, (in millions) 2023 2022 2021 Finance lease cost Amortization of leased assets $ 109 $ 120 $ 131 Interest of lease liabilities 42 45 55 Operating lease cost (1) 981 949 863 Short-term lease cost (1) 258 281 245 Variable lease cost (1) 2,230 1,859 1,599 Total lease cost $ 3,620 $ 3,254 $ 2,893 (1) Expenses are primarily classified within aircraft rent, landing fees and other rents and regional carrier expense on our income statement. Other Information The table below presents supplemental cash flow information related to leases. Supplemental lease-related cash flow information Year Ended December 31, (in millions) 2023 2022 2021 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows for operating leases $ 1,230 $ 809 $ 999 Operating cash flows for finance leases 71 49 46 Financing cash flows for finance leases 264 363 336 Undiscounted Cash Flows The table below reconciles the undiscounted cash flows for each of the first five years and total of the remaining years to the finance lease liabilities and operating lease liabilities recorded on the balance sheets. Future lease cash flows and reconciliation to the balance sheet (in millions) Operating Leases Finance Leases 2024 $ 1,021 $ 395 2025 990 257 2026 899 192 2027 860 391 2028 772 164 Thereafter 4,705 157 Total minimum lease payments 9,247 1,556 Less: amount of lease payments representing interest (2,020) (112) Present value of future minimum lease payments 7,227 1,444 Less: current obligations under leases (759) (358) Long-term lease obligations $ 6,468 $ 1,086 As of December 31, 2023, we had additional leases that had not yet commenced of $151 million. These leases will commence in 2024 with lease terms of 4 to 19 years.
LEASES	LEASES We lease property and equipment under finance and operating leases. For leases with terms greater than 12 months, we record the related asset and obligation at the present value of the fixed minimum lease payments over the term. Many of our leases include rental escalation clauses, renewal options and/or termination options that are factored into our determination of lease payments when appropriate. We do not separate lease and nonlease components of contracts, except for regional aircraft and information technology ("IT") assets as discussed below. We use the rate implicit in the lease to discount lease payments to present value, when readily determinable. As the rate implicit in the lease is rarely readily determinable, we use our incremental borrowing rate, which is based on the estimated interest rate for collateralized borrowing over a similar term of the lease at commencement date. Some of our aircraft lease agreements include provisions for residual value guarantees. These guarantees represent an immaterial portion of our lease liability. Aircraft As of December 31, 2023, including aircraft operated by our regional carriers, we leased 225 aircraft, of which 111 were under finance leases and 114 were operating leases. Our aircraft leases had remaining lease terms of five months to 12 years. In addition, we have regional aircraft leases that are embedded within our capacity purchase agreements and included in the ROU asset and lease liability. We allocated the consideration in each capacity purchase agreement to the lease and nonlease components based on their relative standalone fair values. Lease components of these agreements consist of 116 aircraft as of December 31, 2023 and nonlease components primarily consist of flight operations, in-flight and maintenance services. We determined our best estimate of the standalone fair value of the individual components by considering observable information including rates paid by our wholly owned subsidiary, Endeavor Air, Inc., and rates published by independent valuation firms. See Note 10, "Commitments and Contingencies," for additional information about our capacity purchase agreements. Airport Facilities Our facility leases are primarily for space at approximately 300 airports around the world that we serve. These leases reflect our use of airport terminals, office space, cargo warehouses and maintenance facilities. We generally lease space from government agencies that control the use of the airport, and as a result, these leases are classified as operating leases. The remaining lease terms vary from one month to 29 years. At the majority of the U.S. airports, the lease rates depend on airport operating costs or use of the facilities and are reset at least annually. Because of the variable nature of the rates, these leases are not recorded on our balance sheets as a ROU asset and lease liability. Some airport facilities have fixed payment schedules, the most significant of which are New York-LaGuardia and New York-JFK. For those airport leases, we have recorded a ROU asset and lease liability representing the fixed component of the lease payments. See Note 8, "Airport Redevelopment," for more information on our significant airport redevelopment projects. Other Ground Property and Equipment We lease certain IT assets (including servers, mainframes, etc.), ground support equipment (including tugs, tractors, fuel trucks and de-icers), and various other equipment. The remaining lease terms range from one month to six years. Certain leased assets are embedded within various ground and IT service agreements. For ground service contracts, we have elected to include both the lease and nonlease components in the lease asset and lease liability balances on our balance sheets. For IT service contracts, we have elected to separate the lease and nonlease components and only the lease components are included in the lease asset and lease liability balances on our balance sheets. The amounts of these lease and nonlease components are not significant. Lease Position The table below presents the lease-related assets and liabilities recorded on the balance sheets. Lease asset and liability balance sheet position by category December 31, (in millions) Classification on the Balance Sheet 2023 2022 Assets Operating lease assets Operating lease right-of-use assets $ 7,004 $ 7,036 Finance lease assets Property and equipment, net 1,338 1,487 Total lease assets $ 8,342 $ 8,523 Liabilities Current Operating Current maturities of operating leases $ 759 $ 714 Finance Current maturities of debt and finance leases 358 304 Noncurrent Operating Noncurrent operating leases 6,468 6,866 Finance Debt and finance leases 1,086 1,345 Total lease liabilities $ 8,671 $ 9,229 Weighted-average remaining lease term Operating leases 13 years 13 years Finance leases 4 years 5 years Weighted-average discount rate Operating leases 3.73 % 4.30 % Finance leases 3.12 % 3.05 % Lease Costs The table below presents certain information related to the lease costs for finance and operating leases. Lease cost by category Year Ended December 31, (in millions) 2023 2022 2021 Finance lease cost Amortization of leased assets $ 109 $ 120 $ 131 Interest of lease liabilities 42 45 55 Operating lease cost (1) 981 949 863 Short-term lease cost (1) 258 281 245 Variable lease cost (1) 2,230 1,859 1,599 Total lease cost $ 3,620 $ 3,254 $ 2,893 (1) Expenses are primarily classified within aircraft rent, landing fees and other rents and regional carrier expense on our income statement. Other Information The table below presents supplemental cash flow information related to leases. Supplemental lease-related cash flow information Year Ended December 31, (in millions) 2023 2022 2021 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows for operating leases $ 1,230 $ 809 $ 999 Operating cash flows for finance leases 71 49 46 Financing cash flows for finance leases 264 363 336 Undiscounted Cash Flows The table below reconciles the undiscounted cash flows for each of the first five years and total of the remaining years to the finance lease liabilities and operating lease liabilities recorded on the balance sheets. Future lease cash flows and reconciliation to the balance sheet (in millions) Operating Leases Finance Leases 2024 $ 1,021 $ 395 2025 990 257 2026 899 192 2027 860 391 2028 772 164 Thereafter 4,705 157 Total minimum lease payments 9,247 1,556 Less: amount of lease payments representing interest (2,020) (112) Present value of future minimum lease payments 7,227 1,444 Less: current obligations under leases (759) (358) Long-term lease obligations $ 6,468 $ 1,086 As of December 31, 2023, we had additional leases that had not yet commenced of $151 million. These leases will commence in 2024 with lease terms of 4 to 19 years.

AIRPORT REDEVELOPMENT

AIRPORT REDEVELOPMENT	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
AIRPORT REDEVELOPMENT	AIRPORT REDEVELOPMENT New York-JFK Airport We are enhancing and expanding our facilities at Terminal 4 of JFK to strengthen our competitive position and offer a premium travel experience for customers in New York City. Terminal 4 is operated by JFK International Air Terminal LLC ("IAT"), a private party, under its lease with the Port Authority of New York and New Jersey ("Port Authority"). We have a long-term agreement with IAT to sublease space in Terminal 4 through 2043 ("Sublease"). In 2021, the Port Authority approved plans to renovate and expand Terminal 4 in order to facilitate Delta's relocation from Terminal 2 and consolidation of its operations into Terminal 4. The project is adding 10 new gates and other complementary facilities, including an additional Delta Sky Club and a new Delta premium lounge. The project is estimated to cost approximately $1.6 billion and will be funded primarily with bonds issued in 2022 by the NYTDC for which our landlord, IAT, is the obligor. The majority of project costs are being used to expand or modify Delta's leased premises. Construction started in late 2021 and in 2023 we substantially completed a majority of Delta's portion of the project and consolidated all operations to Terminal 4. Based on our assessment of the project, we concluded that we do not control the underlying assets being constructed, and therefore, we do not have the project asset or related obligation recorded on our balance sheets. Equity Investment. We have an equity method investment in JFK IAT Member LLC, which owns IAT. The Sublease requires us to pay certain fixed management fees. We determined the investment is a variable interest entity and assessed whether we have a controlling financial interest in IAT. Our rights under the Sublease, with respect to management of Terminal 4, are consistent with rights granted to an anchor tenant under a standard airport lease. Accordingly, we do not consolidate this entity in our Consolidated Financial Statements. See Note 4, "Investments" for additional information on our equity investments. Los Angeles International Airport ("LAX") As part of the terminal redevelopment project at LAX, we are modernizing, upgrading, and providing post-security connection to Terminals 2 and 3. We announced this project and executed a modified lease agreement during 2016 with the City of Los Angeles (the "City"), which owns and operates LAX. This project includes a new centralized ticketing and arrival hall, a new security checkpoint, core infrastructure to support the City's planned airport people mover, ramp improvements and a post-security connector to the north side of the Tom Bradley International Terminal. The project is expected to cost approximately $2.4 billion. A substantial majority of the project costs are being funded through the Regional Airports Improvement Corporation ("RAIC"), a California public benefit corporation, using a revolving credit facility provided by a group of lenders. The credit facility was executed in 2017 and we have guaranteed the obligations of the RAIC under the credit facility. During 2023, the revolving credit facility agreement was amended and the revolver capacity was reduced to $626 million. Loans made under the credit facility are being repaid with the proceeds from the City’s purchase of completed project assets. Under the lease agreement and subsequent project component approvals by the City's Board of Airport Commissioners, the City has appropriated to date approximately $1.8 billion to purchase completed project assets, representing the maximum allowable reimbursement by the City. Costs incurred in excess of the $1.8 billion maximum will not be reimbursed by the City. We currently expect our net project costs to be approximately $600 million, of which approximately $350 million has been reflected as investing activities and approximately $200 million as operating activities in our cash flows statement since the project started in 2017. In 2020, we enhanced the project’s scope to include a more customer-friendly design of Terminal 3, an expanded Delta Sky Club and baggage system upgrades designed to increase the terminals’ operational efficiency going forward. In 2023, we substantially completed all construction for this project. Based on our assessment of the project, we concluded that we do not control the underlying assets being constructed, and therefore, we do not have the project asset or related obligation recorded on our balance sheets, except for certain assets recorded as leasehold improvements within property and equipment, net on our balance sheets. We have recorded approximately $200 million as a ROU asset on our balance sheets related to certain costs incurred in excess of RAIC funding, though we have not recognized a ROU asset and lease liability on our balance sheets for the variable lease payments in our agreement with the City. See Note 7, "Leases" for more information on our ROU assets and lease liabilities. New York-LaGuardia Airport As part of the terminal redevelopment project at LaGuardia Airport, we are partnering with the Port Authority to replace Terminals C and D with a new state-of-the-art terminal facility consisting of 37 gates across four concourses connected to a central headhouse. The completed terminal redevelopment features a new, larger Delta Sky Club, wider concourses, more gate seating and nearly double the amount of concessions space than the prior terminals. The completed facility also offers direct access between the parking garage and terminal and improved roadways and drop-off/pick-up areas. Construction is underway and is being phased to limit passenger inconvenience. We have opened Concourse E, Concourse G, the headhouse (including the Delta Sky Club), the terminal roadways and portions of Concourse D and Concourse F. Due to an acceleration effort that commenced in 2020, substantial completion is expected by the end of 2024. In connection with the redevelopment, during 2017, we entered into an amended and restated terminal lease with the Port Authority with a term through 2050. Pursuant to the lease agreement, as amended to date, we (1) are funding (through debt issuance and existing cash) and undertaking the design, management and construction of the terminal and certain off-premises supporting facilities, (2) are receiving a Port Authority contribution of approximately $500 million to facilitate construction of the terminal and other supporting infrastructure, (3) will be responsible for all operations and maintenance during the term of the lease and (4) will have preferential rights to all gates in the terminal subject to Port Authority requirements with respect to accommodation of designated carriers. The project is expected to cost $4.3 billion and the total amount spent to date is approximately $3.7 billion. We currently expect our net project cost to be approximately $3.8 billion and we bear the risks of project construction, including any potential cost over-runs. We entered into loan agreements to fund a portion of the construction, which are recorded on our balance sheets as debt with the proceeds reflected as restricted cash. Using funding primarily provided by these arrangements, we spent approximately $500 million, $650 million and $950 million during 2023, 2022 and 2021, respectively. Based on our assessment of the project, we concluded that we do not control the underlying assets being constructed. Costs incurred by Delta are accounted for as leasehold improvements recorded in property and equipment, net on our balance sheets. See Note 6, "Debt," for additional information on the debt (NYTDC Special Facilities Revenue Bonds) related to this redevelopment project.

EMPLOYEE BENEFIT PLANS

EMPLOYEE BENEFIT PLANS	12 Months Ended
	Dec. 31, 2023
Retirement Benefits [Abstract]
EMPLOYEE BENEFIT PLANS	EMPLOYEE BENEFIT PLANS We sponsor defined benefit and defined contribution pension plans, healthcare plans and disability and survivorship plans for eligible employees and retirees and their eligible family members. Defined Benefit Pension Plans. We sponsor defined benefit pension plans for eligible employees and retirees. These plans are generally closed to new entrants and frozen for future benefit accruals. Our funding obligations for qualified defined benefit plans are governed by the Employee Retirement Income Security Act and any applicable legislation. Under the Pension Protection Act of 2006, we elected alternative funding rules so that the unfunded liability for a frozen defined benefit plan may be amortized over a fixed 17-year period and is calculated using an 8.85% discount rate until the 17-year period expires for all frozen defined benefit plans by the end of 2024. Upon expiration, under legislation passed in 2021, any required funding would be amortized over a rolling 15-year period and calculated using a discount rate of no less than 4.75% through 2030. We have no minimum funding requirements for these plans in 2024 and do not plan to make voluntary contributions during 2024. During 2023, we established a market based cash balance defined benefit pension plan for eligible pilots that is funded by company contributions in excess of IRS limits in the 401(k) plan. Prior to 2023, these contributions were reflected in our cost associated with the defined contribution pension plans shown below. The company funds the plan with cash contributions as benefits are earned and invests those assets. The participants’ benefit is the sum of the contributions made on their behalf plus any positive return on the invested contributions. Defined Contribution Pension Plans. We sponsor several defined contribution plans. These plans generally cover different employee groups and employer contributions vary by plan. The costs associated with our defined contribution pension plans were approximately $1.2 billion, $1.0 billion and $875 million for the years ended December 31, 2023, 2022 and 2021, respectively. Postretirement Healthcare Plans. We sponsor healthcare plans that provide benefits to eligible retirees and their dependents who are under age 65. We have generally eliminated company-paid post age 65 healthcare coverage, except for (1) subsidies available to a limited group of retirees and their dependents, (2) a group of retirees who retired prior to 1987 and (3) retiree medical accounts which provide a fixed dollar amount to eligible employees who retired under the 2012 voluntary workforce reduction programs or under the 2020 voluntary early retirement and separation programs ("voluntary programs"). Postemployment Plans. We provide certain other welfare benefits to eligible former or inactive employees after employment but before retirement, primarily as part of the disability and survivorship plans. Substantially all employees are eligible for benefits under these plans in the event of death and/or disability. Benefits under our postretirement and post employment plans are funded from current assets and employee contributions. Benefit Obligations, Fair Value of Plan Assets and Funded Status Pension Benefits Other Postretirement and Postemployment Benefits December 31, December 31, (in millions) 2023 2022 2023 2022 Benefit obligation at beginning of period $ 15,811 $ 21,073 $ 3,664 $ 4,605 Service cost 95 — 71 70 Interest cost 855 611 200 128 Actuarial loss/(gain) 351 (4,599) 24 (710) Benefits paid, including lump sums and annuities (1,201) (1,274) (485) (447) Plan amendments — — 11 — Participant contributions — — 18 18 Benefit obligation at end of period (1) $ 15,911 $ 15,811 $ 3,503 $ 3,664 Fair value of plan assets at beginning of period $ 15,721 $ 19,502 $ 71 $ 357 Actual gain/(loss) on plan assets 1,142 (2,517) 3 (73) Employer contributions 104 10 426 216 Participant contributions — — 18 18 Benefits paid, including lump sums and annuities (1,201) (1,274) (485) (447) Fair value of plan assets at end of period $ 15,766 $ 15,721 $ 33 $ 71 Funded status at end of period $ (145) $ (90) $ (3,470) $ (3,593) (1) At the end of each year presented, our accumulated benefit obligations for our pension plans are equal to the benefit obligations shown above. During 2023, net actuarial losses increased our benefit obligation primarily due to the decrease in discount rates while net actuarial gains decreased our benefit obligation primarily due to the increase in discount rates during 2022. These gains and losses are recorded in AOCI and reflected in the table below. Amounts are generally amortized from AOCI over the expected future lifetime of plan participants. Balance Sheet Position Pension Benefits Other Postretirement and Postemployment Benefits December 31, December 31, (in millions) 2023 2022 2023 2022 Prepaid pension assets $ 22 $ 27 $ — $ — Current liabilities (9) (9) (404) (369) Noncurrent liabilities (158) (108) (3,066) (3,224) Funded status at end of period $ (145) $ (90) $ (3,470) $ (3,593) Net actuarial (loss)/gain $ (6,474) $ (6,444) $ (162) $ (155) Prior service credit — — 1 18 Total accumulated other comprehensive loss, pre-tax $ (6,474) $ (6,444) $ (161) $ (137) Certain pension plans have benefit obligations in excess of plan assets. These plans have aggregate projected benefit obligations of $8.6 billion and aggregate fair value of plan assets of $8.4 billion at December 31, 2023. Net Periodic Cost/(Benefit) Pension Benefits Other Postretirement and Postemployment Benefits Year Ended December 31, Year Ended December 31, (in millions) 2023 2022 2021 2023 2022 2021 Service cost $ 95 $ — $ — $ 71 $ 70 $ 86 Interest cost 855 611 582 200 128 117 Expected return on plan assets (1,060) (1,319) (1,522) (1) (17) (34) Amortization of prior service credit — — — (5) (5) (6) Recognized net actuarial loss 240 255 354 14 56 55 Settlements — — 2 — — — Net periodic cost/(benefit) $ 130 $ (453) $ (584) $ 279 $ 232 $ 218 Service cost is recorded in salaries and related costs in the income statement, while all other components are recorded within pension and related (expense)/benefit under non-operating expense. Service cost listed under Pension Benefits relates solely to the new market based cash balance defined benefit pension plan discussed above. Assumptions We used the following actuarial assumptions to determine our benefit obligations and our net periodic cost/(benefit) for the periods presented: December 31, Benefit Obligations (1) 2023 2022 Weighted average discount rate 5.31 % 5.62 % Year Ended December 31, Net Periodic Cost/(Benefit) (1) 2023 2022 2021 Weighted average discount rate 5.59 % 2.96 % 2.61 % Weighted average expected long-term rate of return on plan assets 7.00 % 7.00 % 8.98 % Assumed healthcare cost trend rate for the next year (2) 6.25 % 6.50 % 6.25 % (1) Future employee compensation levels do not impact our frozen defined benefit pension plans or other postretirement plans and impact only a small portion of our other postemployment obligation. (2) Healthcare cost trend rate is assumed to decline gradually to 5.00% by 2029 and remain unchanged thereafter. Expected Long-Term Rate of Return. Our expected long-term rate of return on plan assets is based primarily on plan-specific investment studies using historical market return and volatility data. Modest excess return expectations versus some public market indices are incorporated into the return projections based on the actively managed structure of the investment programs and their records of achieving such returns historically. We also expect to receive a premium for investing in less liquid private markets. We review our rate of return on plan assets assumptions annually. Our annual investment performance for one particular year does not, by itself, significantly influence our evaluation. The investment strategy for our defined benefit pension plan assets is to earn a long-term return that meets or exceeds our annualized return target while taking an acceptable level of risk and maintaining sufficient liquidity to pay current benefits and other cash obligations of the plan. This is achieved by investing in a globally diversified mix of public and private equity, fixed income, real assets, hedge funds and other assets and instruments. Our weighted average expected long-term rate of return on assets for net periodic cost/(benefit) for the year ended December 31, 2023 was 7.00%. Life Expectancy. Changes in life expectancy may significantly impact our benefit obligations and future net periodic cost/(benefit). Each year we review information published by the Society of Actuaries and other publicly available information to develop our best estimate of life expectancy for purposes of measuring pension and other postretirement and postemployment benefit obligations. Benefit Payments Benefit payments in the table below are based on the same assumptions used to measure the related benefit obligations. Actual benefit payments may vary significantly from these estimates. Benefits earned under our pension plans are expected to be paid from funded benefit plan trusts, while our other postretirement and postemployment benefits are funded from current assets. The following table summarizes the benefit payments that are expected to be paid in the years ending December 31: Expected future benefit payments (in millions) Pension Benefits Other Postretirement and Postemployment Benefits 2024 $ 1,310 $ 450 2025 1,350 440 2026 1,350 440 2027 1,360 440 2028 1,360 450 2029-2033 6,670 2,190 Plan Assets We have adopted and implemented investment policies for our defined benefit pension plans that incorporate strategic asset allocation mixes intended to best meet the plans' long-term obligations, while maintaining an appropriate level of risk and liquidity. These asset portfolios employ a diversified mix of investments, which are reviewed periodically. Active management strategies are utilized where feasible in an effort to realize investment returns in excess of market indices. Derivatives in the plans are primarily used to manage risk and gain asset class exposure while still maintaining liquidity. As part of these strategies, the plans are required to hold cash collateral associated with certain derivatives. Our investment strategies target a mix of 20-40% growth-seeking assets, 25-35% income-generating assets and 35-45% risk-diversifying assets. Risk diversifying assets include hedge funds implementing long-short, market neutral and relative value strategies that invest primarily in publicly-traded equity, fixed income, foreign currency and commodity securities and are used to improve the impact of active management on the plans. Benefit Plan Assets Measured at Fair Value on a Recurring Basis Benefit plan assets relate to our defined benefit pension plans and certain of our postemployment benefit plans. These investments are presented net of the related benefit obligation in either other noncurrent assets or pension, postretirement and related benefits on the balance sheets depending on the funded status of each plan. See Note 3, "Fair Value Measurements," for a description of the levels within the fair value hierarchy and associated valuation techniques used to measure fair value. The following table shows our benefit plan assets by asset class. Benefit plan assets measured at fair value on a recurring basis December 31, 2023 December 31, 2022 Valuation Technique (in millions) Level 1 Level 2 Total Level 1 Level 2 Total Fixed income and fixed income-related instruments $ 300 $ 1,858 $ 2,158 $ 77 $ 1,366 $ 1,443 (a)(b) Cash equivalents 471 685 1,156 629 265 894 (a) Equities and equity-related instruments 647 122 769 420 25 445 (a) Delta common stock 419 — 419 343 — 343 (a) Real assets 11 236 247 17 170 187 (a) Benefit plan assets $ 1,848 $ 2,901 $ 4,749 $ 1,486 $ 1,826 $ 3,312 Investments measured at net asset value ("NAV") (1) 11,417 12,329 Total benefit plan assets $ 16,166 $ 15,641 (1) Investments that were measured at NAV per share (or its equivalent) as a practical expedient have not been classified in the fair value hierarchy. Fixed Income and Fixed Income-Related Instruments. These investments include corporate bonds, government bonds, collateralized mortgage obligations and other asset-backed securities, and are generally valued at the bid price or the average of the bid and ask price. Prices are based on pricing models, quoted prices of securities with similar characteristics or broker quotes. Fixed income-related instruments include investments in securities traded on exchanges, including listed futures and options, which are valued at the last reported sale prices on the last business day of the year, or if not available, the last reported bid prices. Over-the-counter securities are valued at the bid prices or the average of the bid and ask prices on the last business day of the year from published sources or, if not available, from other sources considered reliable, generally broker quotes. Cash Equivalents. These investments primarily consist of high-quality, short-term obligations that are a part of institutional money market mutual funds that are valued using current market quotations or an appropriate substitute that reflects current market conditions. Equities and Equity-Related Instruments. These investments include common stock and equity-related instruments. Common stock is valued at the closing price reported on the active market on which the individual securities are traded. Equity-related instruments include investments in securities traded on exchanges, including listed futures and options, which are valued at the last reported sale prices on the last business day of the year or, if not available, the last reported bid prices. Over-the-counter securities are valued at the bid prices or the average of the bid and ask prices on the last business day of the year from published sources or, if not available, from other sources considered reliable, generally broker quotes. Delta Common Stock. The Delta common stock investment is managed by an independent fiduciary. Real Assets. These investments include commodities such as precious metals and precious metals-related instruments, some of which are valued at the closing price reported on the active market on which the individual instruments are traded, while others are priced based on pricing models, quoted prices of securities with similar characteristics or broker quotes. The following table summarizes investments measured at fair value based on NAV per share as a practical expedient: Benefit plan investment assets measured at NAV December 31, 2023 December 31, 2022 (in millions) Fair Value Redemption Frequency Redemption Notice Period Fair Value Redemption Frequency Redemption Notice Period Hedge funds and hedge fund-related strategies $ 6,175 (1) 7-180 Days $ 6,730 (1) 2-180 Days Commingled funds, private equity and private equity-related instruments (4) 2,379 (1) (2) 0-45 Days 2,266 (1) (2) 2-45 Days Fixed income and fixed income-related instruments (4) 1,147 (1) 1-180 Days 1,003 (1) 1-180 Days Real assets (4) 893 (2) N/A 819 (2) N/A Other 823 (3) 2-10 Days 1,511 (3) 2-10 Days Total investments measured at NAV $ 11,417 $ 12,329 (1) Various. Includes funds with monthly or more frequent, quarterly and/or custom redemption frequencies as well as funds with a redemption window following the anniversary of the initial investment. (2) Includes private funds that are closed-ended structures in which the plans' investments are generally not eligible for redemption. (3) Includes funds with monthly or more frequent redemptions. (4) Unfunded commitments were $1.3 billion for commingled funds, private equity and private equity-related instruments, $296 million for fixed income and fixed income-related instruments and $584 million for real assets at December 31, 2023. On an annual basis we assess the potential for adjustments to the fair value of all investments. This primarily applies to private equity, private equity-related strategies and real assets. Due to a lag in the availability of data for certain of these investments, we solicit valuation updates from the investment fund managers and use their information and corroborating data from public markets to determine any needed fair value adjustments. Hedge Funds and Hedge Fund-Related Strategies. These investments are primarily made through shares of limited partnerships or similar structures for which a liquid secondary market does not exist. Commingled Funds, Private Equity and Private Equity-Related Instruments. These investments include commingled funds invested in common stock, as well as private equity and private equity-related instruments. Commingled funds are valued based on quoted market prices of the underlying assets owned by the fund. Private equity and private equity-related instruments are typically valued quarterly by the fund managers using valuation models where one or more of the significant inputs into the model cannot be observed and which require the development of assumptions. Fixed Income and Fixed Income-Related Instruments. These investments include private fixed income instruments that are typically valued monthly or quarterly by the fund managers or third-party valuation agents using valuation models where one or more of significant inputs into the model cannot be observed and which require the development of assumptions. Real Assets. These investments include real estate, energy transition, timberland, agriculture and infrastructure. The valuation of real assets requires significant judgment due to the absence of quoted market prices as well as the inherent lack of liquidity and the long-term nature of these assets. Real assets are typically valued quarterly by the fund managers using valuation models where one or more of the significant inputs into the model cannot be observed and which require the development of assumptions . Other. Primarily includes globally-diversified, risk-managed commingled funds consisting mainly of equity, fixed income and commodity exposures. Other We also sponsor defined benefit pension plans for eligible employees in certain foreign countries. These plans did not have a material impact on our Consolidated Financial Statements in any period presented. Profit Sharing Program Our broad-based employee profit sharing program provides that, for each year in which we have an annual pre-tax profit, as defined by the terms of the program, we will pay a specified portion of that profit to employees. In determining the amount of profit sharing, the program defines profit as pre-tax profit adjusted for profit sharing and certain other items.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Aircraft Purchase Commitments Our future aircraft purchase commitments totaled approximately $17.5 billion at December 31, 2023: Aircraft purchase commitments (1) (in millions) Total 2024 $ 3,530 2025 4,230 2026 3,490 2027 3,870 2028 1,650 Thereafter 760 Total $ 17,530 (1) The timing of these commitments is based on our contractual agreements with the aircraft manufacturers and remains uncertain due to supply chain, manufacturing and regulatory constraints. Our future aircraft purchase commitments included the following aircraft at December 31, 2023: Aircraft purchase commitments by fleet type Fleet Type Purchase Commitments A220-300 77 A321-200neo 107 A330-900neo 12 A350-900 16 B-737-10 100 Total 312 Aircraft Orders During 2023, we agreed to acquire one A330-900 with delivery expected to occur in 2025 and exercised purchase rights for 26 A220-300 aircraft with delivery expected to start in 2027. In January 2024, we entered into a purchase agreement with Airbus for 20 A350-1000 aircraft, with an option to purchase an additional 20 widebody aircraft. Deliveries of these aircraft are scheduled to begin in 2026. Contract Carrier Agreements We have contract carrier agreements with regional carriers expiring through 2034. These agreements are structured as either capacity purchase or revenue proration agreements. Capacity Purchase Agreements. Our regional carriers primarily operate for us under capacity purchase agreements. Under these agreements, the regional carriers operate some or all of their aircraft using our flight designator codes, and we control the scheduling, pricing, reservations, ticketing and seat inventories of those aircraft and retain the revenues associated with those flights. We pay those airlines an amount, as defined in the applicable agreement, which is based on a determination of their cost of operating those flights and other factors intended to approximate market rates for those services. The following table shows our minimum obligations under our existing capacity purchase agreements with third-party regional carriers, excluding contract carrier payments accounted for as leases of aircraft, which are described in Note 7, "Leases." The obligations set forth in the table contemplate minimum levels of flying by the regional carriers under the respective agreements and also reflect assumptions regarding certain costs associated with the minimum levels of flying such as the cost of fuel, labor, maintenance, insurance, catering, property tax and landing fees. Accordingly, our actual payments under these agreements could differ materially from the minimum fixed obligations set forth in the table below. Contract carrier minimum obligations (in millions) Amount 2024 $ 1,600 2025 1,540 2026 1,560 2027 1,520 2028 1,260 Thereafter 1,360 Total $ 8,840 Revenue Proration Agreement. As of December 31, 2023, a portion of our contract carrier arrangement with SkyWest Airlines, Inc. was structured as a revenue proration agreement. This revenue proration agreement establishes a fixed dollar or percentage division of revenues for tickets sold to passengers traveling on connecting flight itineraries. Legal Contingencies We are involved in various legal proceedings related to employment practices, environmental issues, commercial disputes, antitrust and other regulatory matters concerning our business. We record liabilities for losses from legal proceedings when we determine that it is probable that the outcome in a legal proceeding will be unfavorable and the amount of loss can be reasonably estimated. Although the outcome of the legal proceedings in which we are involved cannot be predicted with certainty, we believe that the resolution of current matters will not have a material adverse effect on our Consolidated Financial Statements. Credit Card Processing Agreements Our VISA/MasterCard and American Express credit card processing agreements provide that no cash reserve ("Reserve") is required, and no withholding of payment related to receivables collected will occur, except in certain circumstances, including when we do not maintain a required level of liquidity as outlined in the merchant processing agreements. In circumstances in which the credit card processor can establish a Reserve or withhold payments, the amount of the Reserve or payments that may be withheld would be equal to the potential liability of the credit card processor for tickets purchased with VISA/MasterCard or American Express credit cards, as applicable, that had not yet been used for travel. We did not have a Reserve or an amount withheld as of December 31, 2023 or 2022. Other Contingencies General Indemnifications We are the lessee under many commercial real estate leases. It is common in these transactions for us, as the lessee, to agree to indemnify the lessor and the lessor's related parties for tort, environmental and other liabilities that arise out of or relate to our use or occupancy of the leased premises. This type of indemnity would typically make us responsible to indemnified parties for liabilities arising out of the conduct of, among others, contractors, licensees and invitees at, or in connection with, the use or occupancy of the leased premises. This indemnity often extends to related liabilities arising from the negligence of the indemnified parties, but usually excludes any liabilities caused by either their sole or gross negligence or their willful misconduct. Our aircraft and other equipment lease and financing agreements typically contain provisions requiring us, as the lessee or obligor, to indemnify the other parties to those agreements, including certain of those parties' related persons, against virtually any liabilities that might arise from the use or operation of the aircraft or other equipment. We believe that our insurance would cover most of our exposure to liabilities and related indemnities associated with the commercial real estate leases and aircraft and other equipment lease and financing agreements described above. While our insurance does not typically cover environmental liabilities, we have insurance policies in place as required by applicable environmental laws. Some of our aircraft and other financing transactions include provisions that require us to make payments to preserve an expected economic return to the lenders if that economic return is diminished due to specified changes in law or regulations. In some of these financing transactions, we also bear the risk of changes in tax laws that would subject payments to non-U.S. lenders to withholding taxes. We cannot reasonably estimate our potential future payments under the indemnities and related provisions described above because we cannot predict (1) when and under what circumstances these provisions may be triggered and (2) the amount that would be payable if the provisions were triggered because the amounts would be based on facts and circumstances existing at such time. Employees Under Collective Bargaining Agreements As of December 31, 2023, we had approximately 103,000 full-time equivalent employees, approximately 20% of whom were represented by unions. Domestic airline employees represented by collective bargaining agreements by group Employee Group Approximate Number of Union Date on which Collective Delta Pilots 16,960 ALPA December 31, 2026 Delta Flight Superintendents (Dispatchers) 490 PAFCA November 1, 2024 Endeavor Pilots 1,530 ALPA January 1, 2029 Endeavor Flight Attendants 1,600 AFA March 31, 2027 Delta pilots ratified a new four four In addition to the domestic airline employee groups discussed above, approximately 200 refinery employees of our wholly owned subsidiary Monroe are represented by the United Steel Workers under an agreement that expires on February 28, 2026. This agreement is governed by the National Labor Relations Act, which generally allows either party to engage in self-help upon the expiration of the agreement. Certain of our employees outside the U.S. are represented by unions, work councils or other local representative groups. Other We have certain contracts for goods and services that require us to pay a penalty, acquire inventory specific to us or purchase contract-specific equipment, as defined by each respective contract, if we terminate the contract without cause prior to its expiration date. Because these obligations are contingent on our termination of the contract without cause prior to its expiration date, no obligation would exist unless such a termination occurs.

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES Income Tax Provision Components of income tax provision Year Ended December 31, (in millions) 2023 2022 2021 Current tax provision: Federal $ — $ — $ — State and local (8) (1) (1) International (11) (4) (3) Deferred tax (provision) benefit: Federal (896) (525) (130) State and local (84) (66) 16 Income tax provision $ (999) $ (596) $ (118) The following table presents the principal reasons for the difference between the effective tax rate and the U.S. federal statutory income tax rate: Reconciliation of statutory federal income tax rate to the effective income tax rate Year Ended December 31, 2023 2022 2021 U.S. federal statutory income tax rate 21.0 % 21.0 % 21.0 % State taxes, net of federal benefit 2.0 3.0 (4.4) Permanent differences 0.7 1.0 4.9 Valuation allowance (5.0) 7.3 9.1 Other (0.9) (1.1) (0.8) Effective income tax rate 17.8 % 31.2 % 29.8 % Deferred Taxes Deferred income taxes reflect the net tax effect of temporary differences between the carrying amounts of assets and liabilities for financial reporting and income tax purposes. Significant components of deferred income tax assets and liabilities December 31, (in millions) 2023 2022 Deferred tax assets: Net operating loss carryforwards $ 1,217 $ 1,395 Capital loss carryforward 8 50 Pension, postretirement and other benefits 1,488 1,467 Investments 806 1,106 Deferred revenue 2,110 2,334 Lease liabilities 2,193 2,376 Other 709 682 Valuation allowance (877) (1,176) Total deferred tax assets $ 7,654 $ 8,234 Deferred tax liabilities: Depreciation $ 5,570 $ 5,110 Operating lease assets 1,533 1,624 Intangible assets 1,143 1,121 Other 73 78 Total deferred tax liabilities $ 8,319 $ 7,933 Balance Sheet Position: Other noncurrent assets $ 243 $ 325 Deferred income taxes, net (908) (24) Net deferred tax (liabilities) assets $ (665) $ 301 Valuation Allowance We periodically assess whether it is more likely than not that we will generate sufficient taxable income to realize our deferred income tax assets. We establish valuation allowances if it is more likely than not that we will be unable to realize our deferred income tax assets. In making this determination, we consider available positive and negative evidence and make certain assumptions. We consider, among other things, projected future taxable income, scheduled reversals of deferred tax liabilities, the overall business environment, our historical financial results and tax planning strategies. At December 31, 2023 our net deferred tax liability balance was $665 million, including an $877 million valuation allowance primarily related to certain net realized and unrealized capital losses and certain state net operating losses. As of December 31, 2023, we had approximately $4.5 billion of U.S. federal pre-tax net operating loss carryforwards which we are expecting to utilize by the end of 2025. Approximately $800 million of these net operating loss carryforwards were generated prior to 2018 and will not begin to expire until 2029, while the remaining net operating loss carryforwards do not expire. Therefore, we have not recorded a valuation allowance on our deferred tax assets other than the certain net realized and unrealized capital losses and certain state net operating losses that have short expiration periods. The following table presents the balance of our valuation allowance on our deferred income tax assets and the associated activity: Valuation allowance activity (in millions) 2023 2022 Balance at January 1 $ 1,176 $ 833 Tax provision (299) 155 Equity investment activity — 188 Balance at December 31 $ 877 $ 1,176 Other The amount of, and changes to, our uncertain tax positions were not material in any of the years presented. We are currently under audit by the IRS for the 2023 and 2022 tax years.

EQUITY AND EQUITY COMPENSATION

EQUITY AND EQUITY COMPENSATION	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
EQUITY AND EQUITY COMPENSATION	EQUITY AND EQUITY COMPENSATION Equity We are authorized to issue 2.0 billion shares of capital stock, of which up to 1.5 billion may be shares of common stock, par value $0.0001 per share, and up to 500 million may be shares of preferred stock. Preferred Stock. We may issue preferred stock in one or more series. The Board of Directors is authorized (1) to fix the descriptions, powers (including voting powers), preferences, rights, qualifications, limitations and restrictions with respect to any series of preferred stock and (2) to specify the number of shares of any series of preferred stock. We have not issued any preferred stock. Treasury Stock. We generally withhold shares of Delta common stock to cover employees' portion of required tax withholdings when employee equity awards are issued or vest. These shares are valued at cost, which equals the market price of the common stock on the date of issuance or vesting. The weighted average cost per share held in treasury was $30.37 and $29.73 as of December 31, 2023 and 2022, respectively. Warrants. During 2020 and 2021, in connection with the Coronavirus Aid, Relief, and Economic Security Act of 2020 (the "CARES Act") payroll support program ("PSP") and extensions, we issued warrants to the U.S Department of the Treasury to acquire more than 11.1 million shares of Delta common stock. The number of warrants outstanding slightly increased and the exercise price of the warrants slightly decreased since December 31, 2022 due to dividend payments during 2023. Key terms under each program as of December 31, 2023 are as follows: Summary of payroll support program warrants (in millions) Number of Warrants Exercise Price Expiration Year Payroll Support Program (PSP1) 6.8 $ 24.25 2025 Payroll Support Program Extension (PSP2) 2.4 39.54 2026 Payroll Support Program 3 (PSP3) 1.9 47.57 2026 Total 11.1 Government Grant Recognition. Under the initial payroll support program under the CARES Act and PSP extensions we received support payments of grants, which included $4.5 billion of grants during the year ended December 31, 2021. The grants received from PSP2 and PSP3 were recognized in government grant recognition in our income statement during 2021 over the period that the funds were intended to compensate. Equity Compensation Our broad-based equity and cash compensation plan provides for grants of restricted stock, restricted stock units, stock options, performance awards, including cash incentive awards and other equity-based awards (the "Plan"). Shares of common stock issued under the Plan may be made available from authorized, but unissued, common stock or common stock we acquire. If any shares of our common stock are covered by an award that expires, is canceled, forfeited or otherwise terminates without delivery of shares (including shares surrendered or withheld for payment of taxes related to an award), such shares will again be available for issuance under the Plan except for (1) any shares tendered in payment of an option, (2) shares withheld to satisfy any tax withholding obligation with respect to the exercise of an option or stock appreciation right ("SAR") or (3) shares covered by a stock-settled SAR or other awards that were not issued upon the settlement of the award. The Plan authorizes the issuance of up to 163 million shares of common stock. As of December 31, 2023, there were 13 million shares available for future grants. We make long-term incentive awards annually to eligible employees under the Plan. Generally, awards vest over time, subject to the employee's continued employment. Equity compensation expense, including awards payable in common stock or cash, is recognized in salaries and related costs over the employee's requisite service period (generally, the vesting period of the award) and totaled $180 million, $150 million and $149 million for the years ended December 31, 2023, 2022 and 2021, respectively. We record expense on a straight-line basis for awards with installment vesting. As of December 31, 2023, unrecognized costs related to unvested shares and stock options totaled $103 million. We expect substantially all unvested awards to vest and recognize forfeitures as they occur. Restricted Stock. Restricted stock is common stock that may not be sold or otherwise transferred for a period of time and is subject to forfeiture in certain circumstances. The fair value of restricted stock awards is based on the closing price of the common stock on the grant date. As of December 31, 2023, there were 4.2 million unvested restricted stock awards. Restricted stock activity under the Plan for the years ended December 31, 2023, 2022 and 2021 is as follows: Restricted Stock Award Activity 2023 2022 2021 Restricted Weighted-Average Restricted Weighted-Average Restricted Weighted-Average (in millions, except weighted avg grant price) Outstanding at January 1 3.1 $ 43.43 2.9 $ 45.66 2.2 $ 54.06 Granted 2.7 39.63 1.9 42.45 2.3 39.93 Vested (1.5) 44.79 (1.6) 46.31 (1.4) 51.15 Forfeited (0.1) 40.94 (0.1) 45.51 (0.2) 44.01 Outstanding at December 31 4.2 $ 40.51 3.1 $ 43.43 2.9 $ 45.66 Stock Options. Stock options are granted with an exercise price equal to the closing price of Delta common stock on the grant date and generally have a 10-year term. We determine the fair value of stock options at the grant date using an option pricing model. As of December 31, 2023, there were 6.2 million outstanding stock option awards with a weighted average exercise price of $50.42 of which 5.9 million were exercisable. Stock option activity under the Plan for the years ended December 31, 2023, 2022 and 2021 is as follows: Stock Option Activity 2023 2022 2021 Stock Options Weighted-Average Stock Options Weighted-Average Stock Options Weighted-Average (in millions, except weighted avg grant price) Outstanding at January 1 6.2 $ 50.40 6.2 $ 50.41 5.4 $ 52.37 Granted — — — — 1.0 39.78 Exercised (1) — 39.78 — — — — Forfeited (1) — 51.91 — 52.87 (0.2) 49.61 Outstanding at December 31 6.2 $ 50.42 6.2 $ 50.40 6.2 $ 50.41 (1) 2023 exercise and forfeiture and 2022 forfeiture activity in the table above rounds to zero. Performance Awards. Performance awards are dollar-denominated long-term incentive opportunities which, for grants prior to 2021, were payable in Delta stock to executive officers on the payment date and in cash to all other participants. Beginning with the 2021 grants, performance awards are payable in cash to all participants. Potential performance award payments range from 0%-200% of a target level and are contingent upon our achieving certain financial and operational goals over a three-year performance period. As of December 31, 2023, there were no performance awards payable in Delta stock to executive officers. Based on the closing stock price at each respective year end and contingent on achieving the specified performance conditions, the maximum shares that could be issued were 0.7 million and 1.5 million for the years ended December 31, 2022 and 2021, respectively. Performance-Based Restricted Stock Units. Performance-based restricted stock units are long-term incentive opportunities that provide executive officers with the right to receive shares of Delta stock based on our achievement of certain performance conditions at the end of a three-year period. Potential payouts range from 0%-300% of a target level. Based on the closing stock price at year end and contingent on achieving the specified performance conditions, the maximum shares that could be issued were 3.3 million and 1.3 million for the years ended December 31, 2023 and 2022, respectively. There were no outstanding performance-based restricted stock units for the year ended December 31, 2021.

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE LOSS	12 Months Ended
	Dec. 31, 2023
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
ACCUMULATED OTHER COMPREHENSIVE LOSS	ACCUMULATED OTHER COMPREHENSIVE LOSS Components of accumulated other comprehensive loss (in millions) Pension and Other Benefits Liabilities (2) Other Tax Effect Total Balance at January 1, 2021 $ (10,843) $ 41 $ 1,764 $ (9,038) Changes in value 2,077 — (484) 1,593 Reclassifications into earnings (1) 411 — (96) 315 Balance at December 31, 2021 (8,355) 41 1,184 (7,130) Changes in value 1,419 — (330) 1,089 Reclassifications into earnings (1) 312 — (72) 240 Balance at December 31, 2022 (6,624) 41 782 (5,801) Changes in value (303) (1) 71 (233) Reclassifications into earnings (1) 246 — (57) 189 Balance at December 31, 2023 $ (6,681) $ 40 $ 796 $ (5,845) (1) Amounts reclassified from AOCI for pension and other benefits liabilities are recorded in pension and related (expense)/benefit in non-operating expense in the income statement. (2) Includes approximately $755 million of deferred income tax expense as a result of tax law changes and prior valuation allowance releases through continuing operations, that will not be recognized in net income until pension and other benefit obligations are fully extinguished.

SEGMENTS

SEGMENTS	12 Months Ended
	Dec. 31, 2023
Segment Reporting [Abstract]
SEGMENTS	SEGMENTS Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision maker and is used in resource allocation and performance assessments. Our chief operating decision maker is considered to be our executive leadership team. Our executive leadership team regularly reviews discrete information for our two operating segments, which are determined by the products and services provided: our airline segment and our refinery segment. Airline Segment Our airline segment is managed as a single business unit that provides scheduled air transportation for passengers and cargo throughout the U.S. and around the world and includes our loyalty program, as well as other ancillary businesses. This allows us to benefit from an integrated revenue pricing and route network. Our flight equipment forms one fleet, which is deployed through a single route scheduling system. When making resource allocation decisions, our chief operating decision maker evaluates flight profitability data, which considers fleet type and route economics, but gives no weight to the financial impact of the resource allocation decision on a geographic region or mainline/regional carrier basis. Our objective in making resource allocation decisions is to optimize our consolidated financial results. Refinery Segment Our Monroe subsidiary operates the Trainer oil refinery and related assets located near Philadelphia, Pennsylvania, as part of our strategy to mitigate the cost of the refining margin reflected in the price of jet fuel. Monroe's operations include pipelines and terminal assets that allow the refinery to supply jet fuel to our airline operations throughout the Northeastern U.S., including our New York hubs at LaGuardia and JFK. Our refinery segment operates for the benefit of the airline segment by providing jet fuel to the airline segment from its own production and through jet fuel obtained through agreements with third parties. The refinery's production consists of jet fuel, as well as non-jet fuel products. We use several counterparties to exchange the non-jet fuel products produced by the refinery for jet fuel consumed in our airline operations. The gross fair value of the products exchanged under these agreements during the years ended December 31, 2023, 2022 and 2021 was $2.4 billion, $3.5 billion and $2.3 billion, respectively. A refinery is subject to annual Environmental Protection Agency ("EPA") requirements to blend renewable fuels into the gasoline and on-road diesel fuel it produces. A refinery may meet its obligation by blending the necessary volumes of renewable fuels, by purchasing Renewable Identification Numbers ("RINs") in the open market or through a combination of blending and purchasing RINs. Because Monroe is able to blend only a small amount of renewable fuels, it must purchase the majority of its RINs requirement in the secondary market. Renewable fuel compliance costs are accrued in accounts payable each period as the RINs obligation is generated. Purchased RINs are carried at the lower of cost and net realizable value and are recorded in prepaid expenses and other. During 2023, we acquired RINs assets to satisfy substantially all of our 2023 RINs obligation. The RINs asset and obligation are retired when used to satisfy EPA requirements. During 2023, we retired approximately $700 million of our 2021 and 2022 RINs assets to settle our 2021 and 2022 obligations prior to the compliance deadlines. Segment Reporting Segment results are prepared based on our internal accounting methods described below, with reconciliations to consolidated amounts in accordance with GAAP. Our segments are not designed to measure operating income or loss directly related to the products and services included in each segment on a stand-alone basis. Financial information by segment (in millions) Airline Refinery Intersegment Sales/Other Consolidated Year Ended December 31, 2023 Operating revenue $ 54,669 $ 7,572 $ (4,193) (1) $ 58,048 Depreciation and amortization 2,341 94 (94) (2) 2,341 Operating income (2) 5,136 385 5,521 Interest expense, net 834 17 (17) 834 Total assets, end of period 71,529 2,174 (59) 73,644 Capital expenditures 5,088 235 5,323 Year Ended December 31, 2022 Operating revenue $ 45,605 $ 10,706 $ (5,729) (1) $ 50,582 Depreciation and amortization 2,107 93 (93) (2) 2,107 Operating income (2) 2,884 777 3,661 Interest expense, net 1,029 12 (12) 1,029 Total assets, end of period 69,355 3,039 (106) 72,288 Capital expenditures 6,217 149 6,366 Year Ended December 31, 2021 Operating revenue $ 26,670 $ 6,054 $ (2,825) (1) $ 29,899 Depreciation and amortization 1,998 95 (95) (2) 1,998 Operating income/(loss) (2) 1,888 (2) 1,886 Interest expense, net 1,279 7 (7) 1,279 Total assets, end of period 70,417 2,099 (57) 72,459 Capital expenditures 3,188 59 3,247 (1) See table below for detail of the intersegment operating revenue amounts. (2) Refinery segment operating results, including depreciation and amortization, are included within aircraft fuel and related taxes in our income statement. Operating Revenue Intersegment Sales/Other Year Ended December 31, (in millions) 2023 2022 2021 Sales to airline segment (1) $ (1,535) $ (1,976) $ (492) Exchanged products (2) (2,354) (3,475) (2,293) Sales of refined products (304) (278) (40) Total Operating Revenue Intersegment Sales/Other $ (4,193) $ (5,729) $ (2,825) (1) Represents transfers, valued on a market price basis, from the refinery to the airline segment for use in airline operations. We determine market price for jet fuel from the refinery by reference to the market index for the primary delivery location, which is New York Harbor. (2) Represents value of products delivered under our exchange agreements, as discussed above, determined on a market price basis.

EARNINGS PER SHARE

EARNINGS PER SHARE	12 Months Ended
	Dec. 31, 2023
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE We calculate basic earnings per share by dividing net income by the weighted average number of common shares outstanding, excluding restricted shares. We calculate diluted earnings per share by dividing net income by the weighted average number of common shares outstanding plus the dilutive effect of outstanding share-based instruments, including stock options, restricted stock awards and warrants. Antidilutive common stock equivalents excluded from the diluted earnings per share calculation are not material. The following table shows our computation: Basic and diluted earnings per share Year Ended December 31, (in millions, except per share data) 2023 2022 2021 Net income $ 4,609 $ 1,318 $ 280 Basic weighted average shares outstanding 639 638 636 Dilutive effect of share-based instruments 4 3 5 Diluted weighted average shares outstanding 643 641 641 Basic earnings per share $ 7.21 $ 2.07 $ 0.44 Diluted earnings per share $ 7.17 $ 2.06 $ 0.44

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation Delta Air Lines, Inc., a Delaware corporation, provides scheduled air transportation for passengers and cargo throughout the United States ("U.S.") and around the world. Our Consolidated Financial Statements include the accounts of Delta Air Lines, Inc. and our consolidated subsidiaries and have been prepared in accordance with generally accepted accounting principles in the U.S. ("GAAP"). We are not the primary beneficiary of, nor do we have a controlling financial interest in, any variable interest entity. Accordingly, we have not consolidated any variable interest entity. We have marketing alliances with other airlines to enhance our access to domestic and international markets. These arrangements may include codesharing, reciprocal loyalty program benefits, shared or reciprocal access to passenger lounges, joint promotions, common use of airport gates and ticket counters, office co-location and other marketing agreements. We have received antitrust immunity for certain marketing arrangements, which enables us to offer a more integrated route network and develop common sales, marketing and discount programs for customers. Some of our marketing arrangements provide for the sharing of revenues and expenses. Revenues and expenses associated with collaborative arrangements are presented on a gross basis in the applicable line items on our Consolidated Statements of Operations ("income statement"). We have reclassified certain prior period amounts to conform to the current period presentation. Unless otherwise noted, all amounts disclosed are stated before consideration of income taxes.
Use of Estimates	Use of Estimates We are required to make estimates and assumptions when preparing our Consolidated Financial Statements in accordance with GAAP. These estimates and assumptions affect the amounts reported in our Consolidated Financial Statements and the accompanying notes. Actual results could differ materially from those estimates.
Recent Accounting Standards	Recent Accounting Standards Standards Effective in Future Years Fair Value of Equity Investments. In June 2022, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2022-03, "Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions." Under this standard, a contractual restriction on the sale of an equity security is not considered in measuring the security's fair value. The standard also requires certain disclosures for equity securities that are subject to contractual restrictions. The ASU becomes effective January 1, 2024, however we early adopted this standard as of December 31, 2023. The new standard does not impact the valuation of our equity investments, but we have included the newly required disclosures related to the contractual sale restrictions associated with our investment in Wheels Up Experience Inc. ("Wheels Up"). See Note 4, "Investments," for additional details. Segment Reporting. In November 2023, the FASB issued ASU No. 2023-07, "Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures." This standard requires disclosure of significant segment expenses and other segment items by reportable segment. This ASU becomes effective for annual periods beginning in 2024 and interim periods in 2025. We are assessing the impact of this ASU and upon adoption expect that any impact would be limited to additional segment expense disclosures in the footnotes to our Consolidated Financial Statements. Income Taxes. In December 2023, the FASB issued ASU No. 2023-09, "Income Taxes (Topic 740): Improvements to Income Tax Disclosures." This standard enhances disclosures related to income taxes, including the rate reconciliation and information on income taxes paid. This ASU becomes effective January 1, 2025. We are assessing the impact of this ASU and upon adoption may be required to include certain additional disclosures in the footnotes to our Consolidated Financial Statements.
Cash and Cash Equivalents	Short-term, highly liquid investments with maturities of three months or less when purchased are classified as cash and cash equivalents.
Short-Term Investments	Investments with maturities of greater than three months, but not in excess of one year, when purchased are classified as short-term investments and are stated at fair value. Investments with maturities beyond one year when purchased may be classified as short-term investments if they are expected to be available to support our short-term liquidity needs. Our short-term investments in debt securities purchased prior to October 1, 2022 are classified as fair value investments under the fair value option and unrealized gains and losses are recorded in non-operating expense. Our short-term investments in debt securities purchased on or after October 1, 2022 are classified as available-for-sale investments and are stated at fair value with unrealized gains and losses recorded in accumulated other comprehensive income/(loss) ("AOCI"). Realized gains and losses on these investments are recorded in non-operating expense.
Inventories	Inventories Fuel. As part of our strategy to mitigate the cost of the refining margin reflected in the price of jet fuel, our wholly owned subsidiary, Monroe Energy, LLC ("Monroe"), operates the Trainer oil refinery. Refined products (finished goods) and feedstock and blendstock inventories (work-in-process) are both carried at the lower of cost and net realizable value. We use jet fuel in our airline operations that is produced by the refinery and procured through the exchanges with third parties of gasoline, diesel and other refined products ("non-jet fuel products") the refinery produces. Cost is determined using the first-in, first-out method. Costs include the raw material consumed plus direct manufacturing costs (such as labor, utilities and supplies) as incurred and an applicable portion of manufacturing overhead. Expendables Parts and Supplies. Inventories of expendable parts related to flight equipment, which cannot be economically repaired, reconditioned or reused after removal from the aircraft, are carried at moving average cost and charged to aircraft maintenance materials and outside repairs as consumed. An allowance for obsolescence is provided over the remaining useful life of the related fleet. We also provide allowances for parts identified as excess or obsolete to reduce the carrying costs to the lower of cost or net realizable value. These parts are estimated to have residual value of 5% of the original cost.
Accounting for Refinery Related Buy/Sell Agreements	Accounting for Refinery Related Buy/Sell Agreements To the extent that we receive jet fuel for non-jet fuel products exchanged under buy/sell agreements, we account for these transactions as nonmonetary exchanges. We have recorded these nonmonetary exchanges at the carrying amount of the non-jet fuel products transferred within aircraft fuel and related taxes on the income statement.
Derivatives	Derivatives
Property and Equipment, net	Long-Lived Assets three Our tangible assets consist primarily of flight equipment, which is mobile across geographic markets. Accordingly, assets are not allocated to specific geographic regions.
Impairment of Long-Lived Assets	We review flight equipment, ROU assets and other long-lived assets used in operations for impairment losses when events and circumstances indicate the assets may be impaired. Factors which could be indicators of impairment include, but are not limited to (1) a decision to permanently remove flight equipment or other long-lived assets from operations, (2) significant changes in the estimated useful life, (3) significant changes in projected cash flows, (4) permanent and significant declines in fleet fair values and (5) changes to the regulatory environment. For long-lived assets held for sale, we discontinue depreciation and record impairment losses when the carrying amount of these assets is greater than the fair value less the cost to sell. To determine whether impairments exist for aircraft used in operations, we group assets at the fleet type level or at the contract level for aircraft operated by third-party regional carriers (i.e., the lowest level for which there are identifiable cash flows) and then estimate future cash flows based on projections of capacity, passenger mile yield, fuel and labor costs and other relevant factors. If an asset group is impaired, the impairment loss recognized is the amount by which the asset group's carrying amount exceeds its estimated fair value. We estimate aircraft fair values using published sources, appraisals and bids received from third parties, as available.
Income Taxes	Income Taxes We account for deferred income taxes under the liability method. We recognize deferred tax assets and liabilities based on the tax effects of temporary differences between the financial statement and tax basis of assets and liabilities, as measured by current enacted tax rates. Deferred tax assets and liabilities are net by jurisdiction and are recorded as noncurrent on the balance sheets. We have elected to recognize global intangible low tax income in the period it arises and do not recognize deferred taxes for basis differences that may reverse in future years.
Fuel Card Obligation	Fuel Card Obligation
Manufacturers' Credits	Manufacturers' Credits We periodically receive credits in connection with the acquisition of aircraft and engines. These credits are deferred until the aircraft and engines are delivered, and then applied as a reduction to the cost of the related equipment.
Maintenance Costs	Maintenance Costs We record maintenance costs related to our mainline and regional fleets in aircraft maintenance materials and outside repairs and regional carrier expense, respectively. Maintenance costs are expensed as incurred, except for costs incurred under power-by-the-hour contracts, which are expensed based on actual hours flown. Power-by-the-hour contracts transfer certain risk to third-party service providers and fix the amount we pay per flight hour or per flight cycle to the service provider in exchange for maintenance and repairs under a predefined maintenance program. Modifications that enhance the operating performance or extend the useful lives of airframes or engines are capitalized and amortized over the remaining estimated useful life of the asset or the remaining lease term, whichever is shorter.
Advertising Costs	Advertising Costs
Commissions and Merchant Fees	Commissions and Merchant Fees Passenger sales commissions and merchant fees are recognized in passenger commissions and other selling expenses when the related revenue is recognized.
Goodwill and Indefinite-Lived Intangible Assets	Goodwill and Indefinite-Lived Intangible Assets Our goodwill and identifiable intangible assets relate to the airline segment. We apply a fair value-based impairment test to the carrying value of goodwill and indefinite-lived intangible assets on an annual basis (as of October 1) and, if certain events or circumstances indicate that an impairment loss may have been incurred, on an interim basis. We assess the value of our goodwill and indefinite-lived assets under either a qualitative or quantitative approach. Under a qualitative approach, we consider various market factors, including certain of the key assumptions listed below. We analyze these factors to determine if events and circumstances have affected the fair value of goodwill and indefinite-lived intangible assets. If we determine that it is more likely than not that the asset may be impaired, we use the quantitative approach to assess the asset's fair value and the amount of the impairment. Under a quantitative approach, we calculate the fair value of the asset incorporating the key assumptions listed below into our calculation. We value goodwill and indefinite-lived intangible assets primarily using market and income approach valuation techniques. These measurements include the following key assumptions (1) forecasted revenues, expenses and cash flows, (2) current discount rates, (3) observable market transactions and (4) anticipated changes to the regulatory environment (e.g., changes in slot access and/or availability, additional Open Skies agreements or changes to antitrust approvals). These assumptions are consistent with those that hypothetical market participants would use. Because we are required to make estimates and assumptions when evaluating goodwill and indefinite-lived intangible assets for impairment, actual transaction amounts may differ materially from these estimates. We recognize an impairment charge if the asset's carrying value exceeds its estimated fair value. Changes in certain events and circumstances could result in impairment or a change from indefinite-lived to definite-lived. Factors which could cause impairment include, but are not limited to (1) negative trends in our market capitalization, (2) reduced profitability resulting from lower passenger mile yields or higher input costs (primarily related to fuel and employees), (3) lower passenger demand as a result of weakened U.S. and global economies or other factors, (4) interruption to our operations due to a prolonged employee strike, terrorist attack or other reasons, (5) changes to the regulatory environment (e.g., changes in slot access and/or availability, additional Open Skies agreements or changes to antitrust approvals), (6) competitive changes by other airlines and (7) strategic changes to our operations leading to diminished utilization of the intangible assets. Identifiable Intangible Assets. Indefinite-lived assets are not amortized and consist of routes, slots, the Delta tradename and assets related to alliances and collaborative arrangements. Definite-lived intangible assets consist primarily of marketing and maintenance service agreements and are amortized on a straight-line basis or under the undiscounted cash flows method over the estimated economic life of the respective agreements. Costs incurred to renew or extend the term of an intangible asset are expensed as incurred.

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Reconciliation of cash, cash equivalents, and restricted cash	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the Consolidated Balance Sheets ("balance sheets") that sum to the total of the same such amounts shown within the Consolidated Statements of Cash Flows ("cash flows statement"). Reconciliation of cash, cash equivalents and restricted cash December 31, (in millions) 2023 2022 2021 Current assets: Cash and cash equivalents $ 2,741 $ 3,266 $ 7,933 Restricted cash included in prepaid expenses and other 199 138 163 Noncurrent assets: Restricted cash included in other noncurrent assets 455 69 473 Total cash, cash equivalents and restricted cash $ 3,395 $ 3,473 $ 8,569
Summary of property and equipment by classification	The following table summarizes our property and equipment: Property and equipment by classification December 31, (in millions, except for estimated useful life) Estimated Useful Life 2023 2022 Flight equipment (1) 25-34 years $ 40,976 $ 38,091 Ground property and equipment 3-40 years 9,986 8,996 Information technology-related assets 3-15 years 3,307 3,375 Flight and ground equipment under finance leases Shorter of lease term or estimated useful life 1,862 1,950 Advance payments for equipment 1,062 1,067 Less: accumulated depreciation and amortization (2) (21,707) (20,370) Total property and equipment, net $ 35,486 $ 33,109 (1) Includes aircraft and associated engines and parts. (2) Includes accumulated amortization for flight and ground equipment under finance leases in the amount of $525 million and $463 million at December 31, 2023 and 2022, respectively.

REVENUE RECOGNITION (Tables)

REVENUE RECOGNITION (Tables)	12 Months Ended
	Dec. 31, 2023
Revenue from Contract with Customer [Abstract]
Schedule of disaggregation of revenue	Passenger revenue is composed of passenger ticket sales, loyalty travel awards and travel-related services performed in conjunction with a passenger’s flight. Passenger revenue by category Year Ended December 31, (in millions) 2023 2022 2021 Ticket $ 43,596 $ 35,626 $ 19,339 Loyalty travel awards 3,462 2,898 1,786 Travel-related services 1,851 1,694 1,394 Total passenger revenue $ 48,909 $ 40,218 $ 22,519 Other Revenue Year Ended December 31, (in millions) 2023 2022 2021 Refinery $ 3,379 $ 4,977 $ 3,229 Loyalty program 3,093 2,597 1,770 Ancillary businesses 840 846 793 Miscellaneous 1,104 894 556 Total other revenue $ 8,416 $ 9,314 $ 6,348
Schedule loyalty program activity	The table below presents the activity of the current and noncurrent loyalty program deferred revenue, and includes miles earned through travel and miles sold to participating companies, which are primarily through marketing agreements. Loyalty program activity (in millions) 2023 2022 2021 Balance at January 1 $ 7,882 $ 7,559 $ 7,182 Miles earned 4,173 3,419 2,238 Travel miles redeemed (3,462) (2,898) (1,786) Non-travel miles redeemed (173) (198) (75) Balance at December 31 $ 8,420 $ 7,882 $ 7,559
Schedule of revenue by geographic region	Our passenger and operating revenue by geographic region are summarized in the following table: Revenue by geographic region Passenger Revenue Operating Revenue Year Ended December 31, Year Ended December 31, (in millions) 2023 2022 2021 2023 2022 2021 Domestic $ 33,968 $ 30,197 $ 18,468 $ 40,845 $ 38,478 $ 24,320 Atlantic 9,057 6,093 1,777 10,458 7,429 2,537 Latin America 3,798 2,889 1,873 4,292 3,334 2,284 Pacific 2,086 1,039 401 2,453 1,341 758 Total $ 48,909 $ 40,218 $ 22,519 $ 58,048 $ 50,582 $ 29,899

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Schedule of assets (liabilities) measured at fair value on a recurring basis	Assets (Liabilities) Measured at Fair Value on a Recurring Basis (1) December 31, 2023 Valuation Technique (in millions) Total Level 1 Level 2 Level 3 Cash equivalents $ 1,545 $ 1,545 $ — $ — (a) Restricted cash equivalents 653 653 — — (a) Short-term investments U.S. Government securities 859 204 655 — (a) Corporate obligations 218 — 218 — (a) Other fixed income securities 50 — 50 — (a) Long-term investments and related 2,867 2,614 134 119 (a)(b) Hedge derivatives, net Fuel hedge contracts 5 — 5 — (a)(b) December 31, 2022 Valuation Technique (in millions) Total Level 1 Level 2 Level 3 Cash equivalents $ 2,021 $ 2,021 $ — $ — (a) Restricted cash equivalents 206 206 — — (a) Short-term investments U.S. Government securities 1,587 122 1,465 — (a) Corporate obligations 1,614 — 1,614 — (a) Other fixed income securities 67 — 67 — (a) Long-term investments 1,450 1,305 38 107 (a)(b) Hedge derivatives, net Fuel hedge contracts (47) — (47) — (a)(b) (1) See Note 9, "Employee Benefit Plans," for fair value of benefit plan assets.

INVESTMENTS (Tables)

INVESTMENTS (Tables)	12 Months Ended
	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Schedule of fair value investments ownership interest and carrying value	Equity investments ownership interest and carrying value Accounting Treatment Ownership Interest Carrying Value (in millions) December 31, 2023 December 31, 2022 December 31, 2023 December 31, 2022 Air France-KLM Fair Value 3 % 3 % $ 110 $ 97 China Eastern Fair Value 2 % 2 % 134 189 CLEAR Fair Value 6 % 5 % 171 227 Grupo Aeroméxico Equity Method (1) 20 % 20 % 421 412 Hanjin-KAL Fair Value (2) 15 % 15 % 561 296 LATAM Fair Value 10 % 10 % 658 403 Unifi Aviation Equity Method (3) 49 % 49 % 162 165 Wheels Up Fair Value (4) 38 % 21 % 903 54 Other investments Various 337 285 Equity investments $ 3,457 $ 2,128 (1) Results are included in miscellaneous, net in our income statement under non-operating expense. (2) At December 31, 2023, we held 14.8% of the outstanding shares (including common and preferred), and 14.9% of the common shares, of Hanjin KAL. (3) Results are included in contracted services in our income statement as this entity is integral to the operations of our business by providing services at many of our airport locations. (4) See below for additional information about our ownership interest and voting rights.
Schedule of equity method investments ownership interest and carrying value	Equity investments ownership interest and carrying value Accounting Treatment Ownership Interest Carrying Value (in millions) December 31, 2023 December 31, 2022 December 31, 2023 December 31, 2022 Air France-KLM Fair Value 3 % 3 % $ 110 $ 97 China Eastern Fair Value 2 % 2 % 134 189 CLEAR Fair Value 6 % 5 % 171 227 Grupo Aeroméxico Equity Method (1) 20 % 20 % 421 412 Hanjin-KAL Fair Value (2) 15 % 15 % 561 296 LATAM Fair Value 10 % 10 % 658 403 Unifi Aviation Equity Method (3) 49 % 49 % 162 165 Wheels Up Fair Value (4) 38 % 21 % 903 54 Other investments Various 337 285 Equity investments $ 3,457 $ 2,128 (1) Results are included in miscellaneous, net in our income statement under non-operating expense. (2) At December 31, 2023, we held 14.8% of the outstanding shares (including common and preferred), and 14.9% of the common shares, of Hanjin KAL. (3) Results are included in contracted services in our income statement as this entity is integral to the operations of our business by providing services at many of our airport locations. (4) See below for additional information about our ownership interest and voting rights.

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS (Tables)	12 Months Ended
	Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule goodwill and indefinite-lived intangible assets by category	Goodwill and indefinite-lived intangible assets by category Carrying Value at Excess Fair Value at 2023 Testing Date (in millions) December 31, 2023 December 31, 2022 Goodwill $ 9,753 $ 9,753 >100% International routes and slots 2,583 2,583 20% to >100% Airline alliances 1,863 1,863 30% to >100% Delta tradename 850 850 >100% Domestic slots 622 622 60% to >100% Total $ 15,671 $ 15,671
Schedule of definite-lived intangible assets by category	Definite-Lived Intangible Assets Definite-lived intangible assets by category December 31, 2023 December 31, 2022 (in millions) Gross Carrying Value Gross Carrying Value Accumulated Amortization Marketing agreements $ 730 $ (708) $ 730 $ (704) Maintenance contracts 192 (150) 192 (145) Other 54 (53) 54 (53) Total $ 976 $ (911) $ 976 $ (902)

DEBT (Tables)

DEBT (Tables)	12 Months Ended
	Dec. 31, 2023
Debt Disclosure [Abstract]
Schedule of outstanding debt by category	The following table summarizes our debt as of the dates indicated below: Summary of outstanding debt by category Maturity Dates Interest Rate(s) Per Annum at December 31, 2023 December 31, (in millions) 2023 2022 Unsecured Payroll Support Program Loans 2030 to 2031 1.00% $ 3,496 $ 3,496 Unsecured notes 2024 to 2029 2.90% to 7.38% 2,590 2,997 Financing arrangements secured by SkyMiles assets: SkyMiles Notes (1) 2024 to 2028 4.50% and 4.75% 4,518 5,144 SkyMiles Term Loan (1)(2) 2024 to 2027 9.17% 1,772 2,820 NYTDC Special Facilities Revenue Bonds (1) 2024 to 2045 4.00% to 6.00% 3,656 2,838 Financing arrangements secured by aircraft: Certificates (1) 2024 to 2028 2.00% to 8.00% 1,591 1,802 Notes (1)(2) 2024 to 2033 6.72% to 7.65% 165 813 Financing arrangements secured by slots, gates and/or routes: 2020 Senior Secured Notes 2025 7.00% 838 1,542 2018 Revolving Credit Facility (2) 2026 to 2028 Undrawn — — Other financings (1)(2) 2024 to 2030 2.51% to 5.00% 67 67 Other revolving credit facilities (2) 2024 to 2026 Undrawn — — Total secured and unsecured debt 18,693 21,519 Unamortized (discount)/premium and debt issuance cost, net and other (83) (138) Total debt 18,610 21,381 Less: current maturities (2,625) (2,055) Total long-term debt $ 15,985 $ 19,326 (1) Due in installments. (2) Certain financings are comprised of variable rate debt. All variable rates are equal to SOFR (generally subject to a floor) or another index rate plus a specified margin.
Schedule of fair value of outstanding debt	The fair value of debt, shown below, is principally based on reported market values, recently completed market transactions and estimates based on interest rates, maturities, credit risk and underlying collateral. Debt is primarily classified as Level 2 within the fair value hierarchy. Fair value of outstanding debt (in millions) December 31, December 31, Net carrying amount $ 18,610 $ 21,381 Fair value $ 18,400 $ 20,700
Schedule of future debt maturities	The following table summarizes scheduled maturities of our debt for the years succeeding December 31, 2023: Future debt maturities (in millions) Total Debt Amortization of 2024 $ 2,633 $ (49) 2025 2,006 (32) 2026 2,610 (6) 2027 2,315 — 2028 1,884 — Thereafter 7,245 4 Total $ 18,693 $ (83) $ 18,610

LEASES (Tables)

LEASES (Tables)	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Schedule of lease asset and liability balance sheet position by category	The table below presents the lease-related assets and liabilities recorded on the balance sheets. Lease asset and liability balance sheet position by category December 31, (in millions) Classification on the Balance Sheet 2023 2022 Assets Operating lease assets Operating lease right-of-use assets $ 7,004 $ 7,036 Finance lease assets Property and equipment, net 1,338 1,487 Total lease assets $ 8,342 $ 8,523 Liabilities Current Operating Current maturities of operating leases $ 759 $ 714 Finance Current maturities of debt and finance leases 358 304 Noncurrent Operating Noncurrent operating leases 6,468 6,866 Finance Debt and finance leases 1,086 1,345 Total lease liabilities $ 8,671 $ 9,229 Weighted-average remaining lease term Operating leases 13 years 13 years Finance leases 4 years 5 years Weighted-average discount rate Operating leases 3.73 % 4.30 % Finance leases 3.12 % 3.05 %
Schedule of lease cost by category	The table below presents certain information related to the lease costs for finance and operating leases. Lease cost by category Year Ended December 31, (in millions) 2023 2022 2021 Finance lease cost Amortization of leased assets $ 109 $ 120 $ 131 Interest of lease liabilities 42 45 55 Operating lease cost (1) 981 949 863 Short-term lease cost (1) 258 281 245 Variable lease cost (1) 2,230 1,859 1,599 Total lease cost $ 3,620 $ 3,254 $ 2,893 (1) Expenses are primarily classified within aircraft rent, landing fees and other rents and regional carrier expense
Schedule supplemental lease-related cash flow information	The table below presents supplemental cash flow information related to leases. Supplemental lease-related cash flow information Year Ended December 31, (in millions) 2023 2022 2021 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows for operating leases $ 1,230 $ 809 $ 999 Operating cash flows for finance leases 71 49 46 Financing cash flows for finance leases 264 363 336
Schedule of future cash flows and reconciliation to the balance sheet, operating leases	The table below reconciles the undiscounted cash flows for each of the first five years and total of the remaining years to the finance lease liabilities and operating lease liabilities recorded on the balance sheets. Future lease cash flows and reconciliation to the balance sheet (in millions) Operating Leases Finance Leases 2024 $ 1,021 $ 395 2025 990 257 2026 899 192 2027 860 391 2028 772 164 Thereafter 4,705 157 Total minimum lease payments 9,247 1,556 Less: amount of lease payments representing interest (2,020) (112) Present value of future minimum lease payments 7,227 1,444 Less: current obligations under leases (759) (358) Long-term lease obligations $ 6,468 $ 1,086
Schedule of future cash flows and reconciliation to the balance sheet, finance leases	The table below reconciles the undiscounted cash flows for each of the first five years and total of the remaining years to the finance lease liabilities and operating lease liabilities recorded on the balance sheets. Future lease cash flows and reconciliation to the balance sheet (in millions) Operating Leases Finance Leases 2024 $ 1,021 $ 395 2025 990 257 2026 899 192 2027 860 391 2028 772 164 Thereafter 4,705 157 Total minimum lease payments 9,247 1,556 Less: amount of lease payments representing interest (2,020) (112) Present value of future minimum lease payments 7,227 1,444 Less: current obligations under leases (759) (358) Long-term lease obligations $ 6,468 $ 1,086

EMPLOYEE BENEFIT PLANS (Tables)

EMPLOYEE BENEFIT PLANS (Tables)	12 Months Ended
	Dec. 31, 2023
Retirement Benefits [Abstract]
Schedule of benefit obligations, fair value of plan assets, and funded status	Benefit Obligations, Fair Value of Plan Assets and Funded Status Pension Benefits Other Postretirement and Postemployment Benefits December 31, December 31, (in millions) 2023 2022 2023 2022 Benefit obligation at beginning of period $ 15,811 $ 21,073 $ 3,664 $ 4,605 Service cost 95 — 71 70 Interest cost 855 611 200 128 Actuarial loss/(gain) 351 (4,599) 24 (710) Benefits paid, including lump sums and annuities (1,201) (1,274) (485) (447) Plan amendments — — 11 — Participant contributions — — 18 18 Benefit obligation at end of period (1) $ 15,911 $ 15,811 $ 3,503 $ 3,664 Fair value of plan assets at beginning of period $ 15,721 $ 19,502 $ 71 $ 357 Actual gain/(loss) on plan assets 1,142 (2,517) 3 (73) Employer contributions 104 10 426 216 Participant contributions — — 18 18 Benefits paid, including lump sums and annuities (1,201) (1,274) (485) (447) Fair value of plan assets at end of period $ 15,766 $ 15,721 $ 33 $ 71 Funded status at end of period $ (145) $ (90) $ (3,470) $ (3,593) (1) At the end of each year presented, our accumulated benefit obligations for our pension plans are equal to the benefit obligations shown above.
Schedule of amounts balance sheet position	Balance Sheet Position Pension Benefits Other Postretirement and Postemployment Benefits December 31, December 31, (in millions) 2023 2022 2023 2022 Prepaid pension assets $ 22 $ 27 $ — $ — Current liabilities (9) (9) (404) (369) Noncurrent liabilities (158) (108) (3,066) (3,224) Funded status at end of period $ (145) $ (90) $ (3,470) $ (3,593) Net actuarial (loss)/gain $ (6,474) $ (6,444) $ (162) $ (155) Prior service credit — — 1 18 Total accumulated other comprehensive loss, pre-tax $ (6,474) $ (6,444) $ (161) $ (137)
Schedule of net periodic cost (benefit)	Net Periodic Cost/(Benefit) Pension Benefits Other Postretirement and Postemployment Benefits Year Ended December 31, Year Ended December 31, (in millions) 2023 2022 2021 2023 2022 2021 Service cost $ 95 $ — $ — $ 71 $ 70 $ 86 Interest cost 855 611 582 200 128 117 Expected return on plan assets (1,060) (1,319) (1,522) (1) (17) (34) Amortization of prior service credit — — — (5) (5) (6) Recognized net actuarial loss 240 255 354 14 56 55 Settlements — — 2 — — — Net periodic cost/(benefit) $ 130 $ (453) $ (584) $ 279 $ 232 $ 218
Schedule of assumptions used to determine benefit obligations and net periodic costs/ (benefit)	We used the following actuarial assumptions to determine our benefit obligations and our net periodic cost/(benefit) for the periods presented: December 31, Benefit Obligations (1) 2023 2022 Weighted average discount rate 5.31 % 5.62 % Year Ended December 31, Net Periodic Cost/(Benefit) (1) 2023 2022 2021 Weighted average discount rate 5.59 % 2.96 % 2.61 % Weighted average expected long-term rate of return on plan assets 7.00 % 7.00 % 8.98 % Assumed healthcare cost trend rate for the next year (2) 6.25 % 6.50 % 6.25 % (1) Future employee compensation levels do not impact our frozen defined benefit pension plans or other postretirement plans and impact only a small portion of our other postemployment obligation. (2) Healthcare cost trend rate is assumed to decline gradually to 5.00% by 2029 and remain unchanged thereafter.
Schedule of expected future benefit payments	The following table summarizes the benefit payments that are expected to be paid in the years ending December 31: Expected future benefit payments (in millions) Pension Benefits Other Postretirement and Postemployment Benefits 2024 $ 1,310 $ 450 2025 1,350 440 2026 1,350 440 2027 1,360 440 2028 1,360 450 2029-2033 6,670 2,190
Schedule of benefit plan assets measured at fair value on recurring basis	The following table shows our benefit plan assets by asset class. Benefit plan assets measured at fair value on a recurring basis December 31, 2023 December 31, 2022 Valuation Technique (in millions) Level 1 Level 2 Total Level 1 Level 2 Total Fixed income and fixed income-related instruments $ 300 $ 1,858 $ 2,158 $ 77 $ 1,366 $ 1,443 (a)(b) Cash equivalents 471 685 1,156 629 265 894 (a) Equities and equity-related instruments 647 122 769 420 25 445 (a) Delta common stock 419 — 419 343 — 343 (a) Real assets 11 236 247 17 170 187 (a) Benefit plan assets $ 1,848 $ 2,901 $ 4,749 $ 1,486 $ 1,826 $ 3,312 Investments measured at net asset value ("NAV") (1) 11,417 12,329 Total benefit plan assets $ 16,166 $ 15,641 (1) Investments that were measured at NAV per share (or its equivalent) as a practical expedient have not been classified in the fair value hierarchy.
Schedule of benefit plan investments assets measured at NAV	The following table summarizes investments measured at fair value based on NAV per share as a practical expedient: Benefit plan investment assets measured at NAV December 31, 2023 December 31, 2022 (in millions) Fair Value Redemption Frequency Redemption Notice Period Fair Value Redemption Frequency Redemption Notice Period Hedge funds and hedge fund-related strategies $ 6,175 (1) 7-180 Days $ 6,730 (1) 2-180 Days Commingled funds, private equity and private equity-related instruments (4) 2,379 (1) (2) 0-45 Days 2,266 (1) (2) 2-45 Days Fixed income and fixed income-related instruments (4) 1,147 (1) 1-180 Days 1,003 (1) 1-180 Days Real assets (4) 893 (2) N/A 819 (2) N/A Other 823 (3) 2-10 Days 1,511 (3) 2-10 Days Total investments measured at NAV $ 11,417 $ 12,329 (1) Various. Includes funds with monthly or more frequent, quarterly and/or custom redemption frequencies as well as funds with a redemption window following the anniversary of the initial investment. (2) Includes private funds that are closed-ended structures in which the plans' investments are generally not eligible for redemption. (3) Includes funds with monthly or more frequent redemptions. (4) Unfunded commitments were $1.3 billion for commingled funds, private equity and private equity-related instruments, $296 million for fixed income and fixed income-related instruments and $584 million for real assets at December 31, 2023.

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Schedule of aircraft purchase commitments	Our future aircraft purchase commitments totaled approximately $17.5 billion at December 31, 2023: Aircraft purchase commitments (1) (in millions) Total 2024 $ 3,530 2025 4,230 2026 3,490 2027 3,870 2028 1,650 Thereafter 760 Total $ 17,530 (1) The timing of these commitments is based on our contractual agreements with the aircraft manufacturers and remains uncertain due to supply chain, manufacturing and regulatory constraints. Our future aircraft purchase commitments included the following aircraft at December 31, 2023: Aircraft purchase commitments by fleet type Fleet Type Purchase Commitments A220-300 77 A321-200neo 107 A330-900neo 12 A350-900 16 B-737-10 100 Total 312
Schedule of contract carrier minimum obligations	The obligations set forth in the table contemplate minimum levels of flying by the regional carriers under the respective agreements and also reflect assumptions regarding certain costs associated with the minimum levels of flying such as the cost of fuel, labor, maintenance, insurance, catering, property tax and landing fees. Accordingly, our actual payments under these agreements could differ materially from the minimum fixed obligations set forth in the table below. Contract carrier minimum obligations (in millions) Amount 2024 $ 1,600 2025 1,540 2026 1,560 2027 1,520 2028 1,260 Thereafter 1,360 Total $ 8,840
Schedule of domestic airline employees represented by collective bargaining agreements by group	Domestic airline employees represented by collective bargaining agreements by group Employee Group Approximate Number of Union Date on which Collective Delta Pilots 16,960 ALPA December 31, 2026 Delta Flight Superintendents (Dispatchers) 490 PAFCA November 1, 2024 Endeavor Pilots 1,530 ALPA January 1, 2029 Endeavor Flight Attendants 1,600 AFA March 31, 2027

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Schedule of components of income tax benefit (provision)	Components of income tax provision Year Ended December 31, (in millions) 2023 2022 2021 Current tax provision: Federal $ — $ — $ — State and local (8) (1) (1) International (11) (4) (3) Deferred tax (provision) benefit: Federal (896) (525) (130) State and local (84) (66) 16 Income tax provision $ (999) $ (596) $ (118)
Schedule of effective income tax rate reconciliation	The following table presents the principal reasons for the difference between the effective tax rate and the U.S. federal statutory income tax rate: Reconciliation of statutory federal income tax rate to the effective income tax rate Year Ended December 31, 2023 2022 2021 U.S. federal statutory income tax rate 21.0 % 21.0 % 21.0 % State taxes, net of federal benefit 2.0 3.0 (4.4) Permanent differences 0.7 1.0 4.9 Valuation allowance (5.0) 7.3 9.1 Other (0.9) (1.1) (0.8) Effective income tax rate 17.8 % 31.2 % 29.8 %
Schedule of significant components of deferred income tax assets and liabilities	Significant components of deferred income tax assets and liabilities December 31, (in millions) 2023 2022 Deferred tax assets: Net operating loss carryforwards $ 1,217 $ 1,395 Capital loss carryforward 8 50 Pension, postretirement and other benefits 1,488 1,467 Investments 806 1,106 Deferred revenue 2,110 2,334 Lease liabilities 2,193 2,376 Other 709 682 Valuation allowance (877) (1,176) Total deferred tax assets $ 7,654 $ 8,234 Deferred tax liabilities: Depreciation $ 5,570 $ 5,110 Operating lease assets 1,533 1,624 Intangible assets 1,143 1,121 Other 73 78 Total deferred tax liabilities $ 8,319 $ 7,933 Balance Sheet Position: Other noncurrent assets $ 243 $ 325 Deferred income taxes, net (908) (24) Net deferred tax (liabilities) assets $ (665) $ 301
Schedule of valuation allowance on deferred income tax assets	The following table presents the balance of our valuation allowance on our deferred income tax assets and the associated activity: Valuation allowance activity (in millions) 2023 2022 Balance at January 1 $ 1,176 $ 833 Tax provision (299) 155 Equity investment activity — 188 Balance at December 31 $ 877 $ 1,176

EQUITY AND EQUITY COMPENSATION

EQUITY AND EQUITY COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Schedule of warrants	Summary of payroll support program warrants (in millions) Number of Warrants Exercise Price Expiration Year Payroll Support Program (PSP1) 6.8 $ 24.25 2025 Payroll Support Program Extension (PSP2) 2.4 39.54 2026 Payroll Support Program 3 (PSP3) 1.9 47.57 2026 Total 11.1
Schedule of restricted stock activity	Restricted stock activity under the Plan for the years ended December 31, 2023, 2022 and 2021 is as follows: Restricted Stock Award Activity 2023 2022 2021 Restricted Weighted-Average Restricted Weighted-Average Restricted Weighted-Average (in millions, except weighted avg grant price) Outstanding at January 1 3.1 $ 43.43 2.9 $ 45.66 2.2 $ 54.06 Granted 2.7 39.63 1.9 42.45 2.3 39.93 Vested (1.5) 44.79 (1.6) 46.31 (1.4) 51.15 Forfeited (0.1) 40.94 (0.1) 45.51 (0.2) 44.01 Outstanding at December 31 4.2 $ 40.51 3.1 $ 43.43 2.9 $ 45.66
Schedule of stock option activity	Stock option activity under the Plan for the years ended December 31, 2023, 2022 and 2021 is as follows: Stock Option Activity 2023 2022 2021 Stock Options Weighted-Average Stock Options Weighted-Average Stock Options Weighted-Average (in millions, except weighted avg grant price) Outstanding at January 1 6.2 $ 50.40 6.2 $ 50.41 5.4 $ 52.37 Granted — — — — 1.0 39.78 Exercised (1) — 39.78 — — — — Forfeited (1) — 51.91 — 52.87 (0.2) 49.61 Outstanding at December 31 6.2 $ 50.42 6.2 $ 50.40 6.2 $ 50.41 (1) 2023 exercise and forfeiture and 2022 forfeiture activity in the table above rounds to zero.

ACCUMULATED OTHER COMPREHENSI_2

ACCUMULATED OTHER COMPREHENSIVE LOSS (Tables)	12 Months Ended
	Dec. 31, 2023
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of components of accumulated other comprehensive loss	Components of accumulated other comprehensive loss (in millions) Pension and Other Benefits Liabilities (2) Other Tax Effect Total Balance at January 1, 2021 $ (10,843) $ 41 $ 1,764 $ (9,038) Changes in value 2,077 — (484) 1,593 Reclassifications into earnings (1) 411 — (96) 315 Balance at December 31, 2021 (8,355) 41 1,184 (7,130) Changes in value 1,419 — (330) 1,089 Reclassifications into earnings (1) 312 — (72) 240 Balance at December 31, 2022 (6,624) 41 782 (5,801) Changes in value (303) (1) 71 (233) Reclassifications into earnings (1) 246 — (57) 189 Balance at December 31, 2023 $ (6,681) $ 40 $ 796 $ (5,845) (1) Amounts reclassified from AOCI for pension and other benefits liabilities are recorded in pension and related (expense)/benefit in non-operating expense in the income statement. (2) Includes approximately $755 million of deferred income tax expense as a result of tax law changes and prior valuation allowance releases through continuing operations, that will not be recognized in net income until pension and other benefit obligations are fully extinguished.

SEGMENTS (Tables)

SEGMENTS (Tables)	12 Months Ended
	Dec. 31, 2023
Segment Reporting [Abstract]
Schedule of financial information by segment	Segment results are prepared based on our internal accounting methods described below, with reconciliations to consolidated amounts in accordance with GAAP. Our segments are not designed to measure operating income or loss directly related to the products and services included in each segment on a stand-alone basis. Financial information by segment (in millions) Airline Refinery Intersegment Sales/Other Consolidated Year Ended December 31, 2023 Operating revenue $ 54,669 $ 7,572 $ (4,193) (1) $ 58,048 Depreciation and amortization 2,341 94 (94) (2) 2,341 Operating income (2) 5,136 385 5,521 Interest expense, net 834 17 (17) 834 Total assets, end of period 71,529 2,174 (59) 73,644 Capital expenditures 5,088 235 5,323 Year Ended December 31, 2022 Operating revenue $ 45,605 $ 10,706 $ (5,729) (1) $ 50,582 Depreciation and amortization 2,107 93 (93) (2) 2,107 Operating income (2) 2,884 777 3,661 Interest expense, net 1,029 12 (12) 1,029 Total assets, end of period 69,355 3,039 (106) 72,288 Capital expenditures 6,217 149 6,366 Year Ended December 31, 2021 Operating revenue $ 26,670 $ 6,054 $ (2,825) (1) $ 29,899 Depreciation and amortization 1,998 95 (95) (2) 1,998 Operating income/(loss) (2) 1,888 (2) 1,886 Interest expense, net 1,279 7 (7) 1,279 Total assets, end of period 70,417 2,099 (57) 72,459 Capital expenditures 3,188 59 3,247 (1) See table below for detail of the intersegment operating revenue amounts. (2) Refinery segment operating results, including depreciation and amortization, are included within aircraft fuel and related taxes in our income statement. Operating Revenue Intersegment Sales/Other Year Ended December 31, (in millions) 2023 2022 2021 Sales to airline segment (1) $ (1,535) $ (1,976) $ (492) Exchanged products (2) (2,354) (3,475) (2,293) Sales of refined products (304) (278) (40) Total Operating Revenue Intersegment Sales/Other $ (4,193) $ (5,729) $ (2,825) (1) Represents transfers, valued on a market price basis, from the refinery to the airline segment for use in airline operations. We determine market price for jet fuel from the refinery by reference to the market index for the primary delivery location, which is New York Harbor. (2) Represents value of products delivered under our exchange agreements, as discussed above, determined on a market price basis.

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2023
Earnings Per Share [Abstract]
Schedule of computation of basic and diluted (loss)/earnings per share	The following table shows our computation: Basic and diluted earnings per share Year Ended December 31, (in millions, except per share data) 2023 2022 2021 Net income $ 4,609 $ 1,318 $ 280 Basic weighted average shares outstanding 639 638 636 Dilutive effect of share-based instruments 4 3 5 Diluted weighted average shares outstanding 643 641 641 Basic earnings per share $ 7.21 $ 2.07 $ 0.44 Diluted earnings per share $ 7.17 $ 2.06 $ 0.44

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Cash, Cash Equivalents, and Restricted Cash Reconciliation (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 2,741	$ 3,266	$ 7,933
Restricted cash included in prepaid expenses and other	199	138	163
Noncurrent assets:
Restricted cash included in other noncurrent assets	455	69	473
Total cash, cash equivalents and restricted cash	$ 3,395	$ 3,473	$ 8,569	$ 10,055

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Summary of Significant Accounting Policies [Line Items]
Derivative contracts, net	$ 5,000,000	$ 47,000,000
Depreciation and amortization expense related to property and equipment	2,341,000,000	2,107,000,000	$ 1,998,000,000
Amortization of capitalized software	340,000,000	307,000,000	301,000,000
Net book value of capitalized software	932,000,000	891,000,000
Fuel card obligation	1,100,000,000	1,100,000,000
Advertising expense	347,000,000	302,000,000	$ 198,000,000
Fuel Card Obligation
Summary of Significant Accounting Policies [Line Items]
Purchasing card maximum limit	1,100,000,000
Fuel card obligation	$ 1,100,000,000	$ 1,100,000,000
Minimum
Summary of Significant Accounting Policies [Line Items]
Estimated residual value (percent)	5%
Maximum
Summary of Significant Accounting Policies [Line Items]
Estimated residual value (percent)	10%
Software and software development costs | Minimum
Summary of Significant Accounting Policies [Line Items]
Estimated useful life	3 years
Software and software development costs | Maximum
Summary of Significant Accounting Policies [Line Items]
Estimated useful life	15 years

SUMMARY OF SIGNIFICANT ACCOUN_6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Property and Equipment, net (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Less: accumulated depreciation and amortization	$ (21,707)	$ (20,370)
Total property and equipment, net	35,486	33,109
Flight equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 40,976	38,091
Flight equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	25 years
Flight equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	34 years
Ground property and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 9,986	8,996
Ground property and equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Ground property and equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	40 years
Information technology-related assets
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 3,307	3,375
Information technology-related assets | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Information technology-related assets | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	15 years
Flight and ground equipment under finance leases
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,862	1,950
Less: accumulated depreciation and amortization	(525)	(463)
Advance payments for equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,062	$ 1,067

REVENUE RECOGNITION - Passenger

REVENUE RECOGNITION - Passenger Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Operating revenue	$ 58,048	$ 50,582	$ 29,899
Passenger
Disaggregation of Revenue [Line Items]
Operating revenue	48,909	40,218	22,519
Ticket
Disaggregation of Revenue [Line Items]
Operating revenue	43,596	35,626	19,339
Loyalty travel awards
Disaggregation of Revenue [Line Items]
Operating revenue	3,462	2,898	1,786
Travel-related services
Disaggregation of Revenue [Line Items]
Operating revenue	$ 1,851	$ 1,694	$ 1,394

REVENUE RECOGNITION - Narrative

REVENUE RECOGNITION - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Revenue recognized that was previously recorded in air traffic liability	$ 7,400	$ 4,200	$ 2,200
Disaggregation of Revenue [Line Items]
Marketing contracts initial terms, minimum (in years)	1 year
Marketing contracts initial terms, maximum (in years)	13 years
Cash sales of miles from marketing agreements	$ 6,900	5,700	$ 4,100
Majority of new miles, redemption period (in years)	2 years
Air traffic
Disaggregation of Revenue [Line Items]
Deferred revenue (current and noncurrent)		8,300
Loyalty program deferred revenue		$ 100

REVENUE RECOGNITION - Loyalty P

REVENUE RECOGNITION - Loyalty Program Liability (Details) - Loyalty program - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Loyalty Program
Current and noncurrent deferred revenue, beginning	$ 7,882	$ 7,559	$ 7,182
Miles earned	4,173	3,419	2,238
Travel miles redeemed	(3,462)	(2,898)	(1,786)
Non-travel miles redeemed	(173)	(198)	(75)
Current and noncurrent deferred revenue, ending	$ 8,420	$ 7,882	$ 7,559

REVENUE RECOGNITION - Other Rev

REVENUE RECOGNITION - Other Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Operating revenue	$ 58,048	$ 50,582	$ 29,899
Other
Disaggregation of Revenue [Line Items]
Operating revenue	8,416	9,314	6,348
Refinery
Disaggregation of Revenue [Line Items]
Operating revenue	3,379	4,977	3,229
Loyalty program
Disaggregation of Revenue [Line Items]
Operating revenue	3,093	2,597	1,770
Ancillary businesses
Disaggregation of Revenue [Line Items]
Operating revenue	840	846	793
Miscellaneous
Disaggregation of Revenue [Line Items]
Operating revenue	$ 1,104	$ 894	$ 556

Revenue Recognition - Revenue b

Revenue Recognition - Revenue by Geographic Region (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Operating revenue	$ 58,048	$ 50,582	$ 29,899
Domestic
Disaggregation of Revenue [Line Items]
Operating revenue	40,845	38,478	24,320
Atlantic
Disaggregation of Revenue [Line Items]
Operating revenue	10,458	7,429	2,537
Latin America
Disaggregation of Revenue [Line Items]
Operating revenue	4,292	3,334	2,284
Pacific
Disaggregation of Revenue [Line Items]
Operating revenue	2,453	1,341	758
Passenger
Disaggregation of Revenue [Line Items]
Operating revenue	48,909	40,218	22,519
Passenger | Domestic
Disaggregation of Revenue [Line Items]
Operating revenue	33,968	30,197	18,468
Passenger | Atlantic
Disaggregation of Revenue [Line Items]
Operating revenue	9,057	6,093	1,777
Passenger | Latin America
Disaggregation of Revenue [Line Items]
Operating revenue	3,798	2,889	1,873
Passenger | Pacific
Disaggregation of Revenue [Line Items]
Operating revenue	$ 2,086	$ 1,039	$ 401

FAIR VALUE MEASUREMENTS - Fair

FAIR VALUE MEASUREMENTS - Fair Value Measurements on a Recurring Basis (Details) - Recurring - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash equivalents	$ 1,545	$ 2,021
Restricted cash equivalents	653	206
Long-term investments and related	2,867	1,450
U.S. Government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	859	1,587
Corporate obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	218	1,614
Other fixed income securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	50	67
Fuel hedge contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Hedge derivatives, net	5	(47)
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash equivalents	1,545	2,021
Restricted cash equivalents	653	206
Long-term investments and related	2,614	1,305
Level 1 | U.S. Government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	204	122
Level 1 | Corporate obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	0	0
Level 1 | Other fixed income securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	0	0
Level 1 | Fuel hedge contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Hedge derivatives, net	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash equivalents	0	0
Restricted cash equivalents	0	0
Long-term investments and related	134	38
Level 2 | U.S. Government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	655	1,465
Level 2 | Corporate obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	218	1,614
Level 2 | Other fixed income securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	50	67
Level 2 | Fuel hedge contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Hedge derivatives, net	5	(47)
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash equivalents	0	0
Restricted cash equivalents	0	0
Long-term investments and related	119	107
Level 3 | U.S. Government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	0	0
Level 3 | Corporate obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	0	0
Level 3 | Other fixed income securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	0	0
Level 3 | Fuel hedge contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Hedge derivatives, net	$ 0	$ 0

FAIR VALUE MEASUREMENTS- Narrat

FAIR VALUE MEASUREMENTS- Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	$ 1,127	$ 3,268
Fuel hedge contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
(Loss) gain recognized on derivatives	6	$ 394	$ 146
Fuel hedge contracts | Settlement Gains On Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Loss on derivative	58
Fuel hedge contracts | Mark-to-Market
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Gain on derivative	$ 52

INVESTMENTS - Equity Investment

INVESTMENTS - Equity Investments Ownership Interest and Carrying Value (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Equity Investments
Equity investments	$ 3,457	$ 2,128
Air France-KLM
Equity Investments
Ownership Interest	3%	3%
Carrying Value	$ 110	$ 97
China Eastern
Equity Investments
Ownership Interest	2%	2%
Carrying Value	$ 134	$ 189
CLEAR
Equity Investments
Ownership Interest	6%	5%
Carrying Value	$ 171	$ 227
Hanjin-KAL
Equity Investments
Ownership Interest	15%	15%
Carrying Value	$ 561	$ 296
Hanjin-KAL | Common and Preferred Shares
Equity Investments
Ownership Interest	14.80%
Hanjin-KAL | Common Stock
Equity Investments
Ownership Interest	14.90%
LATAM
Equity Investments
Ownership Interest	10%	10%
Carrying Value	$ 658	$ 403
Wheels Up
Equity Investments
Ownership Interest	38%	21%
Carrying Value	$ 903	$ 54
Other investments
Equity Investments
Carrying Value	$ 337	$ 285
Grupo Aeroméxico
Equity Investments
Ownership Interest	20%	20%
Carrying Value	$ 421	$ 412
Unifi Aviation
Equity Investments
Ownership Interest	49%	49%
Carrying Value	$ 162	$ 165

Investments - Narrative (Detail

Investments - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Aug. 15, 2023
Schedule of Equity Method Investments [Line Items]
Gain on investments, net	$ 1,263,000,000	$ (783,000,000)	$ 56,000,000
Virgin Atlantic
Schedule of Equity Method Investments [Line Items]
Carrying value of equity investment	$ 0
Ownership Interest	49%
Unrecognized equity method losses	$ 400,000,000
Wheels Up
Schedule of Equity Method Investments [Line Items]
Liquidity threshold	$ 100,000,000
Ownership Interest	38%	21%
Voting rights, shares held threshold	29.90%
Gain on investments, net	$ 786,000,000
Public float percentage	5%
Wheels Up | Line of Credit | Delta
Schedule of Equity Method Investments [Line Items]
Purchasing card maximum limit	$ 100,000,000			$ 100,000,000
Line of credit				$ 0
Wheels Up | Line of Credit | Secured Debt
Schedule of Equity Method Investments [Line Items]
Debt instrument amount	390,000,000
Wheels Up | Line of Credit | Secured Debt | Delta
Schedule of Equity Method Investments [Line Items]
Debt instrument amount	150,000,000
Wheels Up | Line of Credit | Secured Debt | Other Investors
Schedule of Equity Method Investments [Line Items]
Debt instrument amount	$ 240,000,000
Wheels Up
Schedule of Equity Method Investments [Line Items]
Equity issuable	95%

GOODWILL AND INTANGIBLE ASSET_2

GOODWILL AND INTANGIBLE ASSETS - Valuation of Goodwill and Indefinite-Lived Intangible (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Goodwill and indefinite-lived intangible assets
Goodwill	$ 9,753	$ 9,753
Goodwill and indefinite-lived intangible assets	$ 15,671	15,671
Minimum
Excess Fair Value at 2023 Testing Date
Excess fair value, goodwill (greater than)	100%
International routes and slots
Goodwill and indefinite-lived intangible assets
Indefinite-lived intangibles	$ 2,583	2,583
International routes and slots | Minimum
Excess Fair Value at 2023 Testing Date
Excess fair value, indefinite-lived intangible assets	20%
International routes and slots | Maximum
Excess Fair Value at 2023 Testing Date
Excess fair value, indefinite-lived intangible assets	100%
Airline alliances
Goodwill and indefinite-lived intangible assets
Indefinite-lived intangibles	$ 1,863	1,863
Airline alliances | Minimum
Excess Fair Value at 2023 Testing Date
Excess fair value, indefinite-lived intangible assets	30%
Airline alliances | Maximum
Excess Fair Value at 2023 Testing Date
Excess fair value, indefinite-lived intangible assets (greater than)	100%
Delta tradename
Goodwill and indefinite-lived intangible assets
Indefinite-lived intangibles	$ 850	850
Excess Fair Value at 2023 Testing Date
Excess fair value, indefinite-lived intangible assets (greater than)	100%
Domestic slots
Goodwill and indefinite-lived intangible assets
Indefinite-lived intangibles	$ 622	$ 622
Domestic slots | Minimum
Excess Fair Value at 2023 Testing Date
Excess fair value, indefinite-lived intangible assets	60%
Domestic slots | Maximum
Excess Fair Value at 2023 Testing Date
Excess fair value, indefinite-lived intangible assets (greater than)	100%

GOODWILL AND INTANGIBLE ASSET_3

GOODWILL AND INTANGIBLE ASSETS - Definite-Lived Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Finite-Lived Intangible Assets
Gross carrying value	$ 976	$ 976
Accumulated amortization	(911)	(902)
Marketing agreements
Finite-Lived Intangible Assets
Gross carrying value	730	730
Accumulated amortization	(708)	(704)
Maintenance contracts
Finite-Lived Intangible Assets
Gross carrying value	192	192
Accumulated amortization	(150)	(145)
Other
Finite-Lived Intangible Assets
Gross carrying value	54	54
Accumulated amortization	$ (53)	$ (53)

GOODWILL AND INTANGIBLE ASSET_4

GOODWILL AND INTANGIBLE ASSETS - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 9	$ 9	$ 10
Estimated amortization expense in 2022	8
Estimated amortization expense in 2023	8
Estimated amortization expense in 2024	8
Estimated amortization expense in 2025	8
Estimated amortization expense in 2026	$ 8

DEBT - Summary of Debt (Details

DEBT - Summary of Debt (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Debt, gross	$ 18,693	$ 21,519
Unamortized (discount)/premium and debt issuance cost, net and other	(83)	(138)
Total debt	18,610	21,381
Less: current maturities	(2,625)	(2,055)
Total long-term debt	$ 15,985	19,326
Unsecured Payroll Support Program Loans | Unsecured Debt
Debt Instrument [Line Items]
Maturity dates range, start	Dec. 31, 2030
Maturity dates range, end	Dec. 31, 2031
Interest rate per annum (percent)	1%
Debt, gross	$ 3,496	3,496
Unsecured notes | Unsecured Debt
Debt Instrument [Line Items]
Maturity dates range, start	Dec. 31, 2024
Maturity dates range, end	Dec. 31, 2029
Debt, gross	$ 2,590	2,997
Unsecured notes | Unsecured Debt | Minimum
Debt Instrument [Line Items]
Interest rate per annum (percent)	2.90%
Unsecured notes | Unsecured Debt | Maximum
Debt Instrument [Line Items]
Interest rate per annum (percent)	7.38%
SkyMiles Notes | Secured Debt
Debt Instrument [Line Items]
Maturity dates range, start	Dec. 31, 2024
Maturity dates range, end	Dec. 31, 2028
Debt, gross	$ 4,518	5,144
SkyMiles Notes | Secured Debt | Minimum
Debt Instrument [Line Items]
Interest rate per annum (percent)	4.50%
SkyMiles Notes | Secured Debt | Maximum
Debt Instrument [Line Items]
Interest rate per annum (percent)	4.75%
SkyMiles Term Loan | Secured Debt
Debt Instrument [Line Items]
Maturity dates range, start	Dec. 31, 2024
Maturity dates range, end	Dec. 31, 2027
Interest rate per annum (percent)	9.17%
Debt, gross	$ 1,772	2,820
NYTDC Special Facilities Revenue Bonds, Series 2020 | Bonds
Debt Instrument [Line Items]
Maturity dates range, start	Dec. 31, 2024
Maturity dates range, end	Dec. 31, 2045
Debt, gross	$ 3,656	2,838
NYTDC Special Facilities Revenue Bonds, Series 2020 | Bonds | Minimum
Debt Instrument [Line Items]
Interest rate per annum (percent)	4%
NYTDC Special Facilities Revenue Bonds, Series 2020 | Bonds | Maximum
Debt Instrument [Line Items]
Interest rate per annum (percent)	6%
Financings secured by aircraft - Certificates | Secured Debt
Debt Instrument [Line Items]
Maturity dates range, start	Dec. 31, 2024
Maturity dates range, end	Dec. 31, 2028
Debt, gross	$ 1,591	1,802
Financings secured by aircraft - Certificates | Secured Debt | Minimum
Debt Instrument [Line Items]
Interest rate per annum (percent)	2%
Financings secured by aircraft - Certificates | Secured Debt | Maximum
Debt Instrument [Line Items]
Interest rate per annum (percent)	8%
Financings secured by aircraft - Notes | Secured Debt
Debt Instrument [Line Items]
Maturity dates range, start	Dec. 31, 2024
Maturity dates range, end	Dec. 31, 2033
Debt, gross	$ 165	813
Financings secured by aircraft - Notes | Secured Debt | Minimum
Debt Instrument [Line Items]
Interest rate per annum (percent)	6.72%
Financings secured by aircraft - Notes | Secured Debt | Maximum
Debt Instrument [Line Items]
Interest rate per annum (percent)	7.65%
2020 Senior Secured Notes | Secured Debt
Debt Instrument [Line Items]
Interest rate per annum (percent)	7%
Debt, gross	$ 838	1,542
2018 Revolving Credit Facility | Secured Debt
Debt Instrument [Line Items]
Maturity date	Dec. 31, 2025
2018 Revolving Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Maturity dates range, start	Dec. 31, 2026
Maturity dates range, end	Dec. 31, 2028
Debt, gross	$ 0	0
Other financings | Secured and unsecured Debt
Debt Instrument [Line Items]
Maturity dates range, start	Dec. 31, 2024
Maturity dates range, end	Dec. 31, 2030
Debt, gross	$ 67	67
Other financings | Secured and unsecured Debt | Minimum
Debt Instrument [Line Items]
Interest rate per annum (percent)	2.51%
Other financings | Secured and unsecured Debt | Maximum
Debt Instrument [Line Items]
Interest rate per annum (percent)	5%
Other revolving credit facilities | Revolving Credit Facility
Debt Instrument [Line Items]
Maturity dates range, start	Dec. 31, 2024
Maturity dates range, end	Dec. 31, 2026
Debt, gross	$ 0	$ 0

DEBT - Early Settlement of Outs

DEBT - Early Settlement of Outstanding Notes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Repayment of principal	$ 585
Loss on extinguishment of debt	63	$ 100	$ 319
Secured and unsecured Debt
Debt Instrument [Line Items]
Repurchase amount	1,400
Loss on extinguishment of debt	$ 63

DEBT - Availability Under Revol

DEBT - Availability Under Revolving Credit Facilities (Details) $ in Millions	Dec. 31, 2023 USD ($)
Debt Instrument [Line Items]
Outstanding letters of credit that do not affect availability of revolvers	$ 450
Revolving Credit Facility
Debt Instrument [Line Items]
Proceeds from revolving credit facilities	$ 2,900

DEBT - NYTDC Special Facilities

DEBT - NYTDC Special Facilities Revenue Bonds, Series 2023 (Details) $ in Millions	Dec. 31, 2023 USD ($)
NYTDC Special Facilities Revenue Bonds, Series 2023 | Bonds
Debt Instrument [Line Items]
Debt instrument amount	$ 878

DEBT - 2018 Revolving Credit Fa

DEBT - 2018 Revolving Credit Facility (Details)	3 Months Ended
	Dec. 31, 2023 USD ($) ratingAgency
Line of Credit Facility [Line Items]
Accordion feature	$ 3,650,000,000
Revolving Credit Facility | 3 Year Revolving Credit Facility
Line of Credit Facility [Line Items]
Purchasing card maximum limit	1,325,000,000
Borrowing capacity available for letters of credit	$ 250,000,000
Debt instrument term	3 years
Number of rating agencies with stable rating | ratingAgency	2
Revolving Credit Facility | 5 Year Revolving Credit Facility
Line of Credit Facility [Line Items]
Purchasing card maximum limit	$ 1,325,000,000
Borrowing capacity available for letters of credit	$ 250,000,000
Debt instrument term	5 years
Letter of Credit
Line of Credit Facility [Line Items]
Purchasing card maximum limit	$ 360,000,000
Debt instrument term	3 years

DEBT - Fair Value of Debt (Deta

DEBT - Fair Value of Debt (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Debt Disclosure [Abstract]
Net carrying amount	$ 18,610	$ 21,381
Fair value	$ 18,400	$ 20,700

DEBT - Covenants (Details)

DEBT - Covenants (Details) - SkyMiles program $ in Millions	Dec. 31, 2023 USD ($)
Debt Instrument [Line Items]
Minimum liquidity covenant	$ 2,000
Aggregate limit on sale of pre-paid miles covenant	$ 550

DEBT - Future Maturities (Detai

DEBT - Future Maturities (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Total Debt
2024	$ 2,633
2025	2,006
2026	2,610
2027	2,315
2028	1,884
Thereafter	7,245
Total	18,693	$ 21,519
Amortization of Debt (Discount)/Premium and Debt Issuance Cost, net and other
2024	(49)
2025	(32)
2026	(6)
2027	0
2028	0
Thereafter	4
Total	(83)	(138)
Total debt	$ 18,610	$ 21,381

LEASES - Narrative (Details)

LEASES - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) lease aircraft airport
Lessee, Lease, Description [Line Items]
Leases that have not yet commenced | $	$ 151
Minimum
Lessee, Lease, Description [Line Items]
Leases that have not yet commenced, term of contract	4 years
Maximum
Lessee, Lease, Description [Line Items]
Leases that have not yet commenced, term of contract	19 years
Aircraft
Lessee, Lease, Description [Line Items]
Number of leases	225
Number of finance leases	111
Number of operating leases	114
Lease component of purchase agreements, number of aircraft | aircraft	116
Aircraft | Minimum
Lessee, Lease, Description [Line Items]
Remaining term of operating leases	5 months
Remaining term of finance leases	5 months
Aircraft | Maximum
Lessee, Lease, Description [Line Items]
Remaining term of operating leases	12 years
Remaining term of finance leases	12 years
Airport Facilities
Lessee, Lease, Description [Line Items]
Number of airports with facility space under lease | airport	300
Airport Facilities | Minimum
Lessee, Lease, Description [Line Items]
Remaining term of operating leases	1 month
Airport Facilities | Maximum
Lessee, Lease, Description [Line Items]
Remaining term of operating leases	29 years
Other Ground Property and Equipment | Minimum
Lessee, Lease, Description [Line Items]
Remaining term of operating leases	1 month
Remaining term of finance leases	1 month
Other Ground Property and Equipment | Maximum
Lessee, Lease, Description [Line Items]
Remaining term of operating leases	6 years
Remaining term of finance leases	6 years

LEASES - Lease Position (Detail

LEASES - Lease Position (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Assets
Operating lease assets	$ 7,004	$ 7,036
Finance lease assets	1,338	1,487
Total lease assets	$ 8,342	$ 8,523
Finance lease asset, balance sheet	Property and equipment, net of accumulated depreciation and amortization of $21,707 and $20,370	Property and equipment, net of accumulated depreciation and amortization of $21,707 and $20,370
Liabilities
Current operating lease liabilities	$ 759	$ 714
Current finance lease liabilities	358	304
Long-term lease obligations	6,468	6,866
Noncurrent finance lease liabilities	1,086	1,345
Total lease liabilities	$ 8,671	$ 9,229
Finance lease liability, current, balance sheet	Current maturities of debt and finance leases	Current maturities of debt and finance leases
Finance lease liability, noncurrent, balance sheet	Debt and finance leases	Debt and finance leases
Operating leases, weighted-average remaining lease term	13 years	13 years
Finance leases, weighted-average remaining lease term	4 years	5 years
Operating leases, weighted-average discount rate	3.73%	4.30%
Finance leases, weighted-average discount rate	3.12%	3.05%

LEASES - Lease Costs (Details)

LEASES - Lease Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Finance lease cost, amortization of leased assets	$ 109	$ 120	$ 131
Finance lease cost, interest of lease liabilities	42	45	55
Operating lease cost	981	949	863
Short-term lease cost	258	281	245
Variable lease cost	2,230	1,859	1,599
Total lease cost	$ 3,620	$ 3,254	$ 2,893

LEASES - Other Information (Det

LEASES - Other Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating cash flows for operating leases	$ 1,230	$ 809	$ 999
Operating cash flows for finance leases	71	49	46
Financing cash flows for finance leases	$ 264	$ 363	$ 336

LEASES - Undiscounted Cash Flow

LEASES - Undiscounted Cash Flows (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Operating Leases
2024	$ 1,021
2025	990
2026	899
2027	860
2028	772
Thereafter	4,705
Total minimum lease payments	9,247
Less: amount of lease payments representing interest	(2,020)
Present value of future minimum lease payments	7,227
Less: current obligations under leases	(759)	$ (714)
Long-term lease obligations	6,468	6,866
Finance Leases
2024	395
2025	257
2026	192
2027	391
2028	164
Thereafter	157
Total minimum lease payments	1,556
Less: amount of lease payments representing interest	(112)
Present value of future minimum lease payments	1,444
Less: current obligations under leases	(358)	(304)
Long-term lease obligations	$ 1,086	$ 1,345

AIRPORT REDEVELOPMENT (Details)

AIRPORT REDEVELOPMENT (Details)	12 Months Ended			84 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) gate	Dec. 31, 2023 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2020 concourse gate	Dec. 31, 2018 USD ($)
Agreements and Obligations [Line Items]
Operating lease assets	$ 7,004,000,000	$ 7,036,000,000		$ 7,004,000,000
Financial Guarantee | Revolving Credit Facility
Agreements and Obligations [Line Items]
Aggregate commitments guaranteed					$ 626,000,000
JFK Terminal Redevelopment Project
Agreements and Obligations [Line Items]
Number of new gates | gate			10
Total expected project costs		1,600,000,000
LAX Redevelopment Project
Agreements and Obligations [Line Items]
Total expected project costs	2,400,000,000			2,400,000,000
Expected net projects costs	600,000,000			600,000,000
Project costs reflected as investing cash flows				350,000,000
Project costs reflected as operating cash flows				200,000,000
Operating lease assets	200,000,000			200,000,000
LAX Redevelopment Project | City of Los Angeles
Agreements and Obligations [Line Items]
Total appropriation to date by city	1,800,000,000			1,800,000,000
Maximum reimbursement by city	1,800,000,000			1,800,000,000
LaGuardia Airport Redevelopment Project
Agreements and Obligations [Line Items]
Total expected project costs	4,300,000,000			4,300,000,000
Expected net projects costs	3,800,000,000			3,800,000,000
Number of new gates planned | gate						37
Number of concourses for gates | concourse						4
Port Authority contribution to redevelopment project							$ 500,000,000
Amount spent on project costs	$ 500,000,000	$ 650,000,000	$ 950,000,000	$ 3,700,000,000

EMPLOYEE BENEFIT PLANS - Narrat

EMPLOYEE BENEFIT PLANS - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure
Discount rate for 17-year amortization period of unfunded liability for frozen defined benefit plan (percent)	8.85%
Estimated funding by employer in next fiscal year	$ 0
Defined contribution plan costs	$ 1,200,000,000	$ 1,000,000,000	$ 875,000,000
Assumed healthcare plan pre age	65 years
Assumed healthcare plan post age	65 years
Projected benefit obligation	$ 8,600,000,000
Fair value of plan asset	$ 8,400,000,000
Weighted average expected long-term rate of return on plan assets	7%	7%	8.98%
Profit sharing	$ 1,383,000,000	$ 563,000,000	$ 108,000,000
Growth-seeking assets | Minimum
Defined Benefit Plan Disclosure
Plan assets, target allocations (percent)	20%
Growth-seeking assets | Maximum
Defined Benefit Plan Disclosure
Plan assets, target allocations (percent)	40%
Income-generating assets | Minimum
Defined Benefit Plan Disclosure
Plan assets, target allocations (percent)	25%
Income-generating assets | Maximum
Defined Benefit Plan Disclosure
Plan assets, target allocations (percent)	35%
Risk-diversifying assets | Minimum
Defined Benefit Plan Disclosure
Plan assets, target allocations (percent)	35%
Risk-diversifying assets | Maximum
Defined Benefit Plan Disclosure
Plan assets, target allocations (percent)	45%

EMPLOYEE BENEFIT PLANS - Benefi

EMPLOYEE BENEFIT PLANS - Benefit Obligations, Fair Value of Plan Assets and Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension Benefits
Change in Benefit Obligation
Benefit obligation at beginning of period	$ 15,811	$ 21,073
Service cost	95	0	$ 0
Interest cost	855	611	582
Actuarial loss/(gain)	351	(4,599)
Benefits paid, including lump sums and annuities	(1,201)	(1,274)
Plan amendments	0	0
Participant contributions	0	0
Benefit obligation at end of period	15,911	15,811	21,073
Change in Fair Value of Plan Assets
Fair value of plan assets at beginning of period	15,721	19,502
Actual gain/(loss) on plan assets	1,142	(2,517)
Employer contributions	104	10
Participant contributions	0	0
Benefits paid, including lump sums and annuities	(1,201)	(1,274)
Fair value of plan assets at end of period	15,766	15,721	19,502
Funded Status of Plan
Funded status at end of period	(145)	(90)
Other Postretirement and Postemployment Benefits
Change in Benefit Obligation
Benefit obligation at beginning of period	3,664	4,605
Service cost	71	70	86
Interest cost	200	128	117
Actuarial loss/(gain)	24	(710)
Benefits paid, including lump sums and annuities	(485)	(447)
Plan amendments	11	0
Participant contributions	18	18
Benefit obligation at end of period	3,503	3,664	4,605
Change in Fair Value of Plan Assets
Fair value of plan assets at beginning of period	71	357
Actual gain/(loss) on plan assets	3	(73)
Employer contributions	426	216
Participant contributions	18	18
Benefits paid, including lump sums and annuities	(485)	(447)
Fair value of plan assets at end of period	33	71	$ 357
Funded Status of Plan
Funded status at end of period	$ (3,470)	$ (3,593)

EMPLOYEE BENEFIT PLANS - Balanc

EMPLOYEE BENEFIT PLANS - Balance Sheet Position (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position
Noncurrent liabilities	$ (3,601)	$ (3,707)
Pension Benefits
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position
Prepaid pension assets	22	27
Current liabilities	(9)	(9)
Noncurrent liabilities	(158)	(108)
Funded status at end of period	(145)	(90)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax
Net actuarial (loss)/gain	(6,474)	(6,444)
Prior service credit	0	0
Total accumulated other comprehensive loss, pre-tax	(6,474)	(6,444)
Other Postretirement and Postemployment Benefits
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position
Prepaid pension assets	0	0
Current liabilities	(404)	(369)
Noncurrent liabilities	(3,066)	(3,224)
Funded status at end of period	(3,470)	(3,593)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax
Net actuarial (loss)/gain	(162)	(155)
Prior service credit	1	18
Total accumulated other comprehensive loss, pre-tax	$ (161)	$ (137)

EMPLOYEE BENEFIT PLANS - Net Pe

EMPLOYEE BENEFIT PLANS - Net Periodic Cost/(Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension Benefits
Defined Benefit Plan Disclosure
Service cost	$ 95	$ 0	$ 0
Interest cost	855	611	582
Expected return on plan assets	(1,060)	(1,319)	(1,522)
Amortization of prior service credit	0	0	0
Recognized net actuarial loss	240	255	354
Settlements	0	0	2
Net periodic cost/(benefit)	130	(453)	(584)
Other Postretirement and Postemployment Benefits
Defined Benefit Plan Disclosure
Service cost	71	70	86
Interest cost	200	128	117
Expected return on plan assets	(1)	(17)	(34)
Amortization of prior service credit	(5)	(5)	(6)
Recognized net actuarial loss	14	56	55
Settlements	0	0	0
Net periodic cost/(benefit)	$ 279	$ 232	$ 218

EMPLOYEE BENEFIT PLANS - Assump

EMPLOYEE BENEFIT PLANS - Assumptions Used to Determine Benefit Obligation and Net Periodic Cost/(Benefit) (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure
Weighted average discount rate	5.31%	5.62%
Weighted average expected long-term rate of return on plan assets	7%	7%	8.98%
Assumed healthcare cost trend rate for the next year	6.25%	6.50%	6.25%
Ultimate healthcare cost trend rate	5%
Pension Benefits
Defined Benefit Plan Disclosure
Weighted average discount rate	5.59%	2.96%	2.61%

EMPLOYEE BENEFIT PLANS - Expect

EMPLOYEE BENEFIT PLANS - Expected Benefit Payments (Details) $ in Millions	Dec. 31, 2023 USD ($)
Pension Benefits
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity
2024	$ 1,310
2025	1,350
2026	1,350
2027	1,360
2028	1,360
2029-2033	6,670
Other Postretirement and Postemployment Benefits
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity
2024	450
2025	440
2026	440
2027	440
2028	450
2029-2033	$ 2,190

EMPLOYEE BENEFIT PLANS - Bene_2

EMPLOYEE BENEFIT PLANS - Benefit Plan Assets Measured at Fair Value on Recurring Basis (Details) - Recurring - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Benefit plan assets by asset class
Benefit plan assets	$ 16,166	$ 15,641
Level 1 and Level 2
Benefit plan assets by asset class
Benefit plan assets	4,749	3,312
Level 1 and Level 2 | Fixed income and fixed income-related instruments
Benefit plan assets by asset class
Benefit plan assets	2,158	1,443
Level 1 and Level 2 | Cash equivalents
Benefit plan assets by asset class
Benefit plan assets	1,156	894
Level 1 and Level 2 | Equities and equity-related instruments
Benefit plan assets by asset class
Benefit plan assets	769	445
Level 1 and Level 2 | Delta common stock
Benefit plan assets by asset class
Benefit plan assets	419	343
Level 1 and Level 2 | Real assets
Benefit plan assets by asset class
Benefit plan assets	247	187
Level 1
Benefit plan assets by asset class
Benefit plan assets	1,848	1,486
Level 1 | Fixed income and fixed income-related instruments
Benefit plan assets by asset class
Benefit plan assets	300	77
Level 1 | Cash equivalents
Benefit plan assets by asset class
Benefit plan assets	471	629
Level 1 | Equities and equity-related instruments
Benefit plan assets by asset class
Benefit plan assets	647	420
Level 1 | Delta common stock
Benefit plan assets by asset class
Benefit plan assets	419	343
Level 1 | Real assets
Benefit plan assets by asset class
Benefit plan assets	11	17
Level 2
Benefit plan assets by asset class
Benefit plan assets	2,901	1,826
Level 2 | Fixed income and fixed income-related instruments
Benefit plan assets by asset class
Benefit plan assets	1,858	1,366
Level 2 | Cash equivalents
Benefit plan assets by asset class
Benefit plan assets	685	265
Level 2 | Equities and equity-related instruments
Benefit plan assets by asset class
Benefit plan assets	122	25
Level 2 | Delta common stock
Benefit plan assets by asset class
Benefit plan assets	0	0
Level 2 | Real assets
Benefit plan assets by asset class
Benefit plan assets	236	170
NAV
Benefit plan assets by asset class
Benefit plan assets	$ 11,417	$ 12,329

EMPLOYEE BENEFIT PLANS - Invest

EMPLOYEE BENEFIT PLANS - Investments Measured at NAV (Details) - NAV - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Investments measured at NAV
Fair value of investment measured at NAV	$ 11,417	$ 12,329
Hedge funds and hedge fund-related strategies
Investments measured at NAV
Fair value of investment measured at NAV	$ 6,175	$ 6,730
Hedge funds and hedge fund-related strategies | Minimum
Investments measured at NAV
Redemption notice period	7 days	2 days
Hedge funds and hedge fund-related strategies | Maximum
Investments measured at NAV
Redemption notice period	180 days	180 days
Commingled funds, private equity and private equity-related instruments
Investments measured at NAV
Fair value of investment measured at NAV	$ 2,379	$ 2,266
Unfunded commitments	$ 1,300
Commingled funds, private equity and private equity-related instruments | Minimum
Investments measured at NAV
Redemption notice period	0 days	2 days
Commingled funds, private equity and private equity-related instruments | Maximum
Investments measured at NAV
Redemption notice period	45 days	45 days
Fixed income and fixed income-related instruments
Investments measured at NAV
Fair value of investment measured at NAV	$ 1,147	$ 1,003
Unfunded commitments	$ 296
Fixed income and fixed income-related instruments | Minimum
Investments measured at NAV
Redemption notice period	1 day	1 day
Fixed income and fixed income-related instruments | Maximum
Investments measured at NAV
Redemption notice period	180 days	180 days
Real assets
Investments measured at NAV
Fair value of investment measured at NAV	$ 893	$ 819
Unfunded commitments	584
Other
Investments measured at NAV
Fair value of investment measured at NAV	$ 823	$ 1,511
Other | Minimum
Investments measured at NAV
Redemption notice period	2 days	2 days
Other | Maximum
Investments measured at NAV
Redemption notice period	10 days	10 days

COMMITMENTS AND CONTINGENCIES -

COMMITMENTS AND CONTINGENCIES - Aircraft Purchase Commitments and Contract Carrier Minimum Obligations (Details) $ in Millions	Dec. 31, 2023 USD ($)
Aircraft purchase commitments
Future commitments:
2024	$ 3,530
2025	4,230
2026	3,490
2027	3,870
2028	1,650
Thereafter	760
Total	17,530
Capacity purchase agreements
Future commitments:
2024	1,600
2025	1,540
2026	1,560
2027	1,520
2028	1,260
Thereafter	1,360
Total	$ 8,840

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES - Aircraft Purchase Commitments by Fleet Type (Details) - Aircraft purchase commitments	Dec. 31, 2023 aircraft
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required	312
A220-300
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required	77
A321-200neo
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required	107
A330-900neo
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required	12
A350-900
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required	16
B-737-10
Future Purchase Commitments
Aircraft purchase commitments, minimum quantity required	100

COMMITMENTS AND CONTINGENCIES_3

COMMITMENTS AND CONTINGENCIES - Narrative (Details) $ in Millions	1 Months Ended	3 Months Ended
	Jan. 31, 2024 aircraft	Jun. 30, 2023 aircraft	Dec. 31, 2023 USD ($)
Future aircraft purchase commitments
Future Purchase Commitments
Future aircraft purchase commitments | $			$ 17,530
A330-900
Future Purchase Commitments
Number of aircraft agreed to be acquired		1
A220-300
Future Purchase Commitments
Number of aircraft purchase rights exercised		26
A350-1000 | Subsequent event
Future Purchase Commitments
Number of aircraft agreed to be acquired	20
A350-1000 Widebody | Subsequent event
Future Purchase Commitments
Number of optional additional aircrafts	20

COMMITMENTS AND CONTINGENCIES_4

COMMITMENTS AND CONTINGENCIES - Employees Under Collective Bargaining Agreements Narrative (Details) $ in Millions		3 Months Ended
	Jan. 01, 2023	Mar. 31, 2023 USD ($)	Dec. 31, 2023 employee
Other Commitments [Line Items]
Approximate number of employees | employee			103,000
Percentage of employees represented by unions under collective bargaining agreements			20%
Collective bargaining agreement term	4 years
Employee pay rate increase	18%
Pilot agreement expense | $		$ 735
Adjustments to other benefit-related items | $		$ 130
Monroe refinery employees represented by United Steel Workers
Other Commitments [Line Items]
Approximate number of employees | employee			200

COMMITMENTS AND CONTINGENCIES_5

COMMITMENTS AND CONTINGENCIES - Employees Under Collective Bargaining Agreements (Details)	Dec. 31, 2023 employee
Other Commitments [Line Items]
Approximate Number of Employees Represented	103,000
Delta Pilots
Other Commitments [Line Items]
Approximate Number of Employees Represented	16,960
Delta Flight Superintendents (Dispatchers)
Other Commitments [Line Items]
Approximate Number of Employees Represented	490
Endeavor Pilots
Other Commitments [Line Items]
Approximate Number of Employees Represented	1,530
Endeavor Flight Attendants
Other Commitments [Line Items]
Approximate Number of Employees Represented	1,600

INCOME TAXES - Components of In

INCOME TAXES - Components of Income Tax Benefit (Provision) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current tax provision:
Federal	$ 0	$ 0	$ 0
State and local	(8)	(1)	(1)
International	(11)	(4)	(3)
Deferred tax (provision) benefit:
Federal	(896)	(525)	(130)
State and local	(84)	(66)	16
Income tax provision	$ (999)	$ (596)	$ (118)

INCOME TAXES - Effective Income

INCOME TAXES - Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Effective Income Tax Rate Reconciliation, Percent
U.S. federal statutory income tax rate	21%	21%	21%
State taxes, net of federal benefit	2%	3%	(4.40%)
Permanent differences	0.70%	1%	4.90%
Valuation allowance	(5.00%)	7.30%	9.10%
Other	(0.90%)	(1.10%)	(0.80%)
Effective income tax rate	17.80%	31.20%	29.80%

INCOME TAXES - Deferred Taxes (

INCOME TAXES - Deferred Taxes (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Net operating loss carryforwards	$ 1,217	$ 1,395
Capital loss carryforward	8	50
Pension, postretirement and other benefits	1,488	1,467
Investments	806	1,106
Deferred revenue	2,110	2,334
Lease liabilities	2,193	2,376
Other	709	682
Valuation allowance	(877)	(1,176)	$ (833)
Total deferred tax assets	7,654	8,234
Deferred tax liabilities:
Depreciation	5,570	5,110
Operating lease assets	1,533	1,624
Intangible assets	1,143	1,121
Other	73	78
Total deferred tax liabilities	8,319	7,933
Deferred income taxes, net	243	325
Deferred income taxes, net	(908)	(24)
Net deferred tax (liabilities) assets	$ (665)
Net deferred tax (liabilities) assets		$ 301

INCOME TAXES - Narrative (Detai

INCOME TAXES - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Deferred tax liabilities	$ 665
Valuation allowance	877	$ 1,176	$ 833
U.S. federal
Income Taxes
Operating loss carryforwards	4,500
Operating loss carryforwards beginning to expire in 2029	$ 800

INCOME TAXES - Valuation Allowa

INCOME TAXES - Valuation Allowance (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Valuation allowance activity
Valuation allowance, beginning	$ 1,176	$ 833
Tax provision	(299)	155
Equity investment activity	0	188
Valuation allowance, ending	$ 877	$ 1,176

EQUITY AND EQUITY COMPENSATIO_2

EQUITY AND EQUITY COMPENSATION - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Capital stock, shares authorized (shares)	2,000,000,000
Common stock, authorized (shares)	1,500,000,000	1,500,000,000
Common stock, par value (USD per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (shares)	500,000,000
Treasury stock weighted average cost per share (USD per share)	$ 30.37	$ 29.73
Grant payments received through payroll support program	$ 4,500
Number of shares authorized for issuance under the Plan (shares)	163,000,000
Shares available for future grant (in shares)	13,000,000
Equity compensation expense	$ 180	$ 150	$ 149
Compensation cost not yet recognized	$ 103
Outstanding stock option awards (shares)	6,200,000	6,200,000	6,200,000	5,400,000
Weighted average exercise price of options outstanding (USD per share)	$ 50.42	$ 50.40	$ 50.41	$ 52.37
Number of exercisable stock option awards (shares)	5,900,000
Restricted stock awards
Class of Stock [Line Items]
Unvested restricted stock awards (shares)	4,200,000	3,100,000	2,900,000	2,200,000
Stock options
Class of Stock [Line Items]
Term of award (in years)	10 years
Performance awards
Class of Stock [Line Items]
Shares available for future grant (in shares)		700,000	1,500,000
Performance period (in years)	3 years
Performance awards | Minimum
Class of Stock [Line Items]
Potential performance award payments as percentage of target level	0%
Performance awards | Maximum
Class of Stock [Line Items]
Potential performance award payments as percentage of target level	200%
Performance-Based Restricted Stock Units
Class of Stock [Line Items]
Shares available for future grant (in shares)	3,300,000	1,300,000
Performance period (in years)	3 years
Performance-Based Restricted Stock Units | Minimum
Class of Stock [Line Items]
Potential performance award payments as percentage of target level	0%
Performance-Based Restricted Stock Units | Maximum
Class of Stock [Line Items]
Potential performance award payments as percentage of target level	300%
PSP Warrants | Payroll Support Program
Class of Stock [Line Items]
Number shares called by warrants (in shares)			11,100,000	11,100,000

EQUITY AND EQUITY COMPENSATIO_3

EQUITY AND EQUITY COMPENSATION - Warrants (Details) shares in Millions	Dec. 31, 2023 $ / shares shares
Class of Warrant or Right [Line Items]
Number of Warrants (in shares)	11.1
Payroll Support Program (PSP1)
Class of Warrant or Right [Line Items]
Number of Warrants (in shares)	6.8
Exercise Price (usd per share) | $ / shares	$ 24.25
Payroll Support Program Extension (PSP2)
Class of Warrant or Right [Line Items]
Number of Warrants (in shares)	2.4
Exercise Price (usd per share) | $ / shares	$ 39.54
Payroll Support Program 3 (PSP3)
Class of Warrant or Right [Line Items]
Number of Warrants (in shares)	1.9
Exercise Price (usd per share) | $ / shares	$ 47.57

EQUITY AND EQUITY COMPENSATIO_4

EQUITY AND EQUITY COMPENSATION - Restricted Stock Award Activity (Details) - Restricted Stock - $ / shares shares in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Restricted Stock
Outstanding, beginning (in shares)	3.1	2.9	2.2
Granted (in shares)	2.7	1.9	2.3
Vested (in shares)	(1.5)	(1.6)	(1.4)
Forfeited (in shares)	(0.1)	(0.1)	(0.2)
Outstanding, ending (in shares)	4.2	3.1	2.9
Restricted Stock, Weighted-Average Grant Price
Outstanding, beginning (USD per share)	$ 43.43	$ 45.66	$ 54.06
Granted (USD per share)	39.63	42.45	39.93
Vested (USD per share)	44.79	46.31	51.15
Forfeited (USD per share)	40.94	45.51	44.01
Outstanding, ending (USD per share)	$ 40.51	$ 43.43	$ 45.66

EQUITY AND EQUITY COMPENSATIO_5

EQUITY AND EQUITY COMPENSATION - Stock Option Activity (Details) - $ / shares shares in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Stock Options
Outstanding, beginning (in shares)	6.2	6.2	5.4
Granted (in shares)	0	0	1
Exercised (in shares)	0	0	0
Forfeited (in shares)	0	0	(0.2)
Outstanding, ending (in shares)	6.2	6.2	6.2
Stock Options, Weighted-Average Grant Price
Outstanding, beginning (USD per share)	$ 50.40	$ 50.41	$ 52.37
Granted (USD per share)	0	0	39.78
Exercised (USD per share)	39.78	0	0
Forfeited (USD per share)	51.91	52.87	49.61
Outstanding, ending (USD per share)	$ 50.42	$ 50.40	$ 50.41

ACCUMULATED OTHER COMPREHENSI_3

ACCUMULATED OTHER COMPREHENSIVE LOSS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
AOCI Attributable to Parent, Net of Tax
Beginning balance, tax effect	$ 782	$ 1,184	$ 1,764
Beginning balance	6,582	3,887	1,534
Changes in value, tax effect	71	(330)	(484)
Changes in value (net of tax effect)	(233)	1,089	1,593
Reclassifications into earnings, tax effect	(57)	(72)	(96)
Reclassification into earnings (net of tax effect)	189	240	315
Ending balance, tax effect	796	782	1,184
Ending balance	11,105	6,582	3,887
Deferred income tax expense in AOCI that will not be recognized until obligation is fully extinguished	755	755	755
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax
Beginning balance	(5,801)	(7,130)	(9,038)
Ending balance	(5,845)	(5,801)	(7,130)
Pension and Other Benefits Liabilities
AOCI Attributable to Parent, Net of Tax
Beginning balance, AOCI before tax	(6,624)	(8,355)	(10,843)
Changes in value	(303)	1,419	2,077
Reclassifications into earnings	246	312	411
Ending balance, AOCI before tax	(6,681)	(6,624)	(8,355)
Other
AOCI Attributable to Parent, Net of Tax
Beginning balance, AOCI before tax	41	41	41
Changes in value	(1)	0	0
Reclassifications into earnings	0	0	0
Ending balance, AOCI before tax	$ 40	$ 41	$ 41

SEGMENTS - Narrative (Details)

SEGMENTS - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) segment fleet	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Business Acquisition [Line Items]
Number of operating segments | segment	2
Number of fleets | fleet	1
Operating revenue	$ 58,048	$ 50,582	$ 29,899
Renewable energy asset retired	700
Intersegment Sales/Other
Business Acquisition [Line Items]
Operating revenue	(4,193)	(5,729)	(2,825)
Intersegment Sales/Other | Exchanged products
Business Acquisition [Line Items]
Operating revenue	$ (2,354)	$ (3,475)	$ (2,293)

SEGMENTS - Segment Reporting (D

SEGMENTS - Segment Reporting (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information, Profit (Loss)
Operating revenue	$ 58,048	$ 50,582	$ 29,899
Depreciation and amortization	2,341	2,107	1,998
Operating income (loss)	5,521	3,661	1,886
Interest expense, net	834	1,029	1,279
Total assets, end of period	73,644	72,288	72,459
Capital expenditures	5,323	6,366	3,247
Operating Segments | Airline
Segment Reporting Information, Profit (Loss)
Operating revenue	54,669	45,605	26,670
Depreciation and amortization	2,341	2,107	1,998
Operating income (loss)	5,136	2,884	1,888
Interest expense, net	834	1,029	1,279
Total assets, end of period	71,529	69,355	70,417
Capital expenditures	5,088	6,217	3,188
Operating Segments | Refinery
Segment Reporting Information, Profit (Loss)
Operating revenue	7,572	10,706	6,054
Depreciation and amortization	94	93	95
Operating income (loss)	385	777	(2)
Interest expense, net	17	12	7
Total assets, end of period	2,174	3,039	2,099
Capital expenditures	235	149	59
Intersegment Sales/Other
Segment Reporting Information, Profit (Loss)
Operating revenue	(4,193)	(5,729)	(2,825)
Depreciation and amortization	(94)	(93)	(95)
Interest expense, net	(17)	(12)	(7)
Total assets, end of period	(59)	(106)	(57)
Intersegment Sales/Other | Sales to airline segment
Segment Reporting Information, Profit (Loss)
Operating revenue	(1,535)	(1,976)	(492)
Intersegment Sales/Other | Exchanged products
Segment Reporting Information, Profit (Loss)
Operating revenue	(2,354)	(3,475)	(2,293)
Intersegment Sales/Other | Sales of refined products
Segment Reporting Information, Profit (Loss)
Operating revenue	$ (304)	$ (278)	$ (40)

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings Per Share [Abstract]
Net income	$ 4,609	$ 1,318	$ 280
Basic weighted average shares outstanding (shares)	639	638	636
Dilutive effect of share-based awards (shares)	4	3	5
Diluted weighted average shares outstanding (shares)	643	641	641
Basic earnings per share (USD per share)	$ 7.21	$ 2.07	$ 0.44
Diluted earnings per share (USD per share)	$ 7.17	$ 2.06	$ 0.44