Consolidated Statement of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 977	$ (3,074)	$ 2,300
Adjustments to reconcile net income (loss) to cash provided by (used in) operating activities:
Depreciation and amortization	1,272	1,255	1,219
Impairment of long-lived assets	12	32	0
Unrealized/realized (gain) loss on fuel derivative instruments	(15)	15	0
Deferred income taxes	(21)	(716)	(55)
Gain on sale-leaseback transactions	0	(222)	0
Loss on partial extinguishment of convertible notes	28	0	0
Changes in certain assets and liabilities:
Accounts and other receivables	(701)	(294)	(94)
Other assets	75	415	239
Accounts payable and accrued liabilities	38	231	298
Air traffic liability	591	1,623	440
Other liabilities	(103)	(306)	(277)
Cash collateral received from derivative counterparties	141	9	25
Other, net	28	(95)	(108)
Net cash provided by (used in) operating activities	2,322	(1,127)	3,987
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(505)	(515)	(1,027)
Supplier proceeds	0	428	400
Proceeds from sale-leaseback transactions	0	815	0
Assets constructed for others	(6)	0	0
Purchases of short-term investments	(5,824)	(5,080)	(2,122)
Proceeds from sales of short-term and other investments	5,071	4,336	2,446
Net cash used in investing activities	(1,264)	(16)	(303)
CASH FLOWS FROM FINANCING ACTIVITIES:
Issuance of common stock	0	2,294	0
Proceeds from issuance of long-term debt	0	5,622	0
Proceeds from term loan credit facility	0	3,683	0
Proceeds from revolving credit facility	0	1,000	0
Proceeds from convertible notes	0	2,300	0
Proceeds from Payroll Support Program loan and warrants	1,136	1,016	0
Proceeds from Employee stock plans	51	48	40
Repurchase of common stock	0	(451)	(2,000)
Payments of long-term debt and finance lease obligations			(615)
Payments of term loan credit facility	0	(3,683)	0
Payments of revolving credit facility	0	(1,000)	0
Payments of cash dividends	0	(188)	(372)
Payments of terminated interest rate derivative instruments	0	(59)	0
Payments for repurchases and conversions of convertible debt	(293)	0	0
Capitalized financing items	0	(134)	0
Other, net	77	49	(43)
Net cash provided by (used in) financing activities	359	9,658	(2,990)
NET CHANGE IN CASH AND CASH EQUIVALENTS	1,417	8,515	694
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	11,063	2,548	1,854
CASH AND CASH EQUIVALENTS AT END OF PERIOD	12,480	11,063	2,548
CASH PAYMENTS FOR:
Interest, net of amount capitalized	336	212	88
Income taxes	445	19	779
SUPPLEMENTAL DISCLOSURE OF NONCASH TRANSACTIONS:
Flight equipment acquired against supplier credit memo	569	0	0
Assets constructed for others	309	145	65
Supplier receivables	0	0	428
Remeasurement of right-of-use asset and lease liability	$ 343	$ 0	$ 0