Consolidated Statement 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 (loss)	$ 465	$ 539	$ 977
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	1,522	1,351	1,272
Impairment of long-lived assets	0	35	12
Unrealized mark-to-market adjustment on available for sale securities	(4)	4	0
Unrealized/realized loss on fuel derivative instruments	0	(2)	(15)
Deferred income taxes	159	228	(21)
Loss on extinguishment of debt	0	193	28
Changes in certain assets and liabilities:
Accounts and other receivables	(89)	422	(701)
Other assets	60	(66)	75
Accounts payable and accrued liabilities	1,386	936	38
Air traffic liability	29	525	591
Other liabilities	(137)	(334)	(103)
Cash collateral received from (provided to) derivative counterparties	(56)	(69)	141
Other, net	(171)	28	28
Net cash provided by operating activities	3,164	3,790	2,322
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(3,520)	(3,924)	(505)
Assets constructed for others	(33)	(22)	(6)
Purchases of short-term investments	(6,970)	(5,592)	(5,824)
Proceeds from sales of short-term and other investments	7,591	5,792	5,071
Net cash used in investing activities	(2,932)	(3,746)	(1,264)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from Payroll Support Program loan and warrants	0	0	1,136
Proceeds from Employee stock plans	48	45	51
Payments of long-term debt and finance lease obligations	(85)	(2,437)	(612)
Payments of cash dividends	(428)	0	0
Proceeds of terminated interest rate derivative instruments	23	0	0
Payments for repurchases and conversions of convertible debt	0	(648)	(293)
Other, net	6	8	77
Net cash provided by (used in) financing activities	(436)	(3,032)	359
NET CHANGE IN CASH AND CASH EQUIVALENTS	(204)	(2,988)	1,417
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	9,492	12,480	11,063
CASH AND CASH EQUIVALENTS AT END OF PERIOD	9,288	9,492	12,480
CASH PAYMENTS FOR:
Interest, net of amount capitalized	228	305	336
Income taxes	18	20	445
SUPPLEMENTAL DISCLOSURE OF NON-CASH TRANSACTIONS:
Adoption of Accounting Standards Update 2020-06, Debt	0	245	0
Right-of-use assets acquired under operating leases	82	58	327
Flight equipment acquired against supplier credit memo	0	0	569
Assets constructed for others	0	0	309
Remeasurement of right-of-use asset and lease liability	$ 0	$ 0	$ 343