CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Current Assets
Cash and cash equivalents	$ 647	$ 338
Marketable securities	1,804	2,079
Total cash and marketable securities	2,451	2,417
Receivables - net	341	296
Inventories and supplies - net	122	104
Prepaid expenses	187	163
Asset, Held-for-Sale, Not Part of Disposal Group, Current	385	3
Other Assets, Current	158	57
Total Current Assets	3,644	3,040
Property and Equipment
Aircraft and other flight equipment	10,015	9,053
Other property and equipment	1,756	1,661
Deposits for future flight equipment	538	670
Property and Equipment Total	12,309	11,384
Less accumulated depreciation and amortization	4,283	4,127
Total Property and Equipment - Net	8,026	7,257
Operating Lease, Right-of-Use Asset	1,171	1,471
Goodwill	2,034	2,038
Other noncurrent assets	290	380
Other Assets	3,495	3,889
Total Assets	15,165	14,186
Current Liabilities
Accounts payable	229	221
Accrued wages, vacation and payroll taxes	561	619
Other accrued liabilities	806	846
Operating Lease, Liability, Current	150	228
Current portion of long-term debt	736	276
Total Current Liabilities	5,074	4,493
Long-Term Debt, Net of Current Portion	2,128	1,883
Noncurrent Liabilities
Operating Lease, Liability, Noncurrent	1,113	1,393
Deferred Income Tax Liabilities, Net	662	574
Deferred revenue, noncurrent	1,366	1,374
Obligation for pension and postretirement medical benefits	368	348
Other liabilities	361	305
Other Liabilities and Credits Totals	3,870	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	$ 659	$ 577
Treasury Stock, Common, Shares	10,884,473	9,349,944
Treasury stock (common), at cost: 2020 - 9,349,944 shares; 2020 - 9,349,944 shares	$ (744)	$ (674)
Accumulated other comprehensive loss	(360)	(388)
Retained earnings	4,537	4,300
Total Shareholders' Equity	4,093	3,816
Total Liabilities and Shareholders' Equity	15,165	14,186
Mileage Plan Revenue [Member]
Current Liabilities
Contract with Customer, Liability, Current	1,233	1,123
Contract with Customer, Liability, Current	1,233	1,123
Passenger Revenue [Member]
Current Liabilities
Contract with Customer, Liability, Current	1,359	1,180
Contract with Customer, Liability, Current	$ 1,359	$ 1,180