Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Net Cash Provided by/(Used in) Operating Activities
Net Cash Provided by/(Used in) Operating Activities	$ 2,708	$ (2,507)
Property and equipment additions:
Flight equipment, including advance payments	(961)	(594)
Ground property and equipment, including technology	(1,068)	(757)
Proceeds from sale-leaseback transactions	0	465
Purchase of short-term investments	(10,799)	(8,700)
Redemption of short-term investments	12,158	3,654
Purchase of equity investments	0	(2,099)
Other, net	252	(159)
Net cash used in investing activities	(418)	(8,190)
Cash Flows from Financing Activities:
Proceeds from short-term obligations	0	3,261
Proceeds from long-term obligations	1,902	22,481
Proceeds from sale-leaseback transactions	0	2,306
Payments on debt and finance lease obligations	(4,685)	(2,318)
Repurchase of common stock	0	(344)
Cash dividends	0	(260)
Fuel card obligation	0	364
Other, net	98	(177)
Net cash (used in)/provided by financing activities	(2,685)	25,313
Net (Decrease)/Increase in Cash, Cash Equivalents and Restricted Cash Equivalents	(395)	14,616
Cash, cash equivalents and restricted cash equivalents at beginning of period	10,055	3,730
Cash, cash equivalents and restricted cash equivalents at end of period	9,660	18,346
Non-Cash Transactions:
Flight and ground equipment acquired under finance leases	904	347
Right-of-use assets acquired under operating leases	536	1,062
Other financings	240	115
Current Assets:
Cash and cash equivalents	8,785	16,477
Restricted cash included in prepaid expenses and other	162	189
Noncurrent Assets:
Cash restricted for airport construction	713	1,680
Total cash, cash equivalents and restricted cash equivalents	$ 9,660	$ 18,346