CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Current Assets
Cash and cash equivalents	$ 536	$ 338
Marketable securities	1,906	2,079
Total cash and marketable securities	2,442	2,417
Receivables - net	351	296
Inventories and supplies - net	107	104
Prepaid expenses	187	163
Other Assets, Current	157	60
Total Current Assets	3,244	3,040
Property and Equipment
Aircraft and other flight equipment	9,918	9,053
Other property and equipment	1,714	1,661
Deposits for future flight equipment	550	670
Property and Equipment Total	12,182	11,384
Less accumulated depreciation and amortization	4,219	4,127
Total Property and Equipment - Net	7,963	7,257
Operating Lease, Right-of-Use Asset	1,318	1,471
Goodwill	2,036	2,038
Other noncurrent assets	268	380
Other Assets	3,622	3,889
Total Assets	14,829	14,186
Current Liabilities
Accounts payable	212	221
Accrued wages, vacation and payroll taxes	463	619
Other accrued liabilities	871	846
Operating Lease, Liability, Current	277	228
Current portion of long-term debt	572	276
Total Current Liabilities	5,176	4,493
Long-Term Debt, Net of Current Portion	1,889	1,883
Noncurrent Liabilities
Operating Lease, Liability, Noncurrent	1,148	1,393
Deferred Income Tax Liabilities, Net	606	574
Deferred revenue, noncurrent	1,370	1,374
Obligation for pension and postretirement medical benefits	362	348
Other liabilities	327	305
Other Liabilities and Credits Totals	3,813	3,994
Commitments and Contingencies
Shareholders' Equity
Preferred stock, $0.01 par value, Authorized: 5,000,000 shares, none issued or outstanding	0	0
Common stock, $0.01 par value, Authorized: 400,000,000 shares, Issued: 2021 - 133,792,045 shares; 2020 - 133,567,534 shares, Outstanding: 2021 - 124,442,101 shares; 2020 - 124,217,590 shares	1	1
Capital in excess of par value	$ 648	$ 577
Treasury Stock, Common, Shares	10,635,485	9,349,944
Treasury stock (common), at cost: 2020 - 9,349,944 shares; 2020 - 9,349,944 shares	$ (731)	$ (674)
Accumulated other comprehensive loss	(365)	(388)
Retained earnings	4,398	4,300
Total Shareholders' Equity	3,951	3,816
Total Liabilities and Shareholders' Equity	14,829	14,186
Mileage Plan Revenue [Member]
Current Liabilities
Contract with Customer, Liability, Current	1,207	1,123
Contract with Customer, Liability, Current	1,207	1,123
Passenger Revenue [Member]
Current Liabilities
Contract with Customer, Liability, Current	1,574	1,180
Contract with Customer, Liability, Current	$ 1,574	$ 1,180