Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Net Cash Provided by Operating Activities
Net Cash Provided by Operating Activities	$ 2,557	$ 68
Property and equipment additions:
Flight equipment, including advance payments	(527)	(659)
Ground property and equipment, including technology	(672)	(559)
Proceeds from sale-leaseback transactions	0	465
Purchase of short-term investments	(5,587)	(4,955)
Redemption of short-term investments	6,494	654
Purchase of equity investments	0	(2,099)
Other, net	258	107
Net cash used in investing activities	(34)	(7,046)
Cash Flows from Financing Activities:
Proceeds from short-term obligations	0	3,261
Proceeds from long-term obligations	1,902	11,747
Proceeds from sale-leaseback transactions	0	2,306
Payments on debt and finance lease obligations	(3,133)	(1,712)
Repurchase of common stock	0	(344)
Cash dividends	0	(260)
Fuel card obligation	0	103
Other, net	111	(35)
Net cash (used in)/provided by financing activities	(1,120)	15,066
Net Increase in Cash, Cash Equivalents and Restricted Cash Equivalents	1,403	8,088
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	11,458	11,818
Non-Cash Transactions:
Flight and ground equipment acquired under finance leases	779	213
Right-of-use assets acquired under operating leases	259	393
Other financings	240	0
Current Assets:
Cash and cash equivalents	10,357	11,366
Restricted cash included in prepaid expenses and other	172	113
Noncurrent Assets:
Cash restricted for airport construction	929	339
Total cash, cash equivalents and restricted cash equivalents	$ 11,458	$ 11,818