CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 1,370	$ 221
Marketable securities	1,976	1,300
Total cash and marketable securities	3,346	1,521
Receivables - net	480	323
Inventories and supplies - net	57	72
Prepaid expenses and other current assets	123	121
Total Current Assets	4,006	2,037
Property and Equipment
Aircraft and other flight equipment	7,761	8,549
Other property and equipment	1,398	1,306
Deposits for future flight equipment	583	533
Property and Equipment	9,742	10,388
Less accumulated depreciation and amortization	3,531	3,486
Total Property and Equipment - Net	6,211	6,902
Other Assets
Operating Lease, Right-of-Use Asset	1,400	1,711
Goodwill	1,943	1,943
Intangible assets - net	107	122
Other noncurrent assets	379	278
Total Other Assets	3,829	4,054
Total Assets	14,046	12,993
Current Liabilities
Accounts payable	108	146
Accrued wages, vacation and payroll taxes	527	470
Other accrued liabilities	424	431
Operating Lease, Liability, Current	290	269
Current portion of long-term debt	1,138	235
Total Current Liabilities	4,293	3,201
Long-Term Debt, Net of Current Portion	2,357	1,264
Other Liabilities and Credits
Operating Lease, Liability, Noncurrent	1,268	1,439
Deferred Income Tax Liabilities, Net	407	715
Deferred revenue	1,544	1,240
Obligation for pension and postretirement medical benefits	665	571
Other liabilities	524	232
Total Other Liabilities and Credits	4,408	4,197
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: 2020 - 133,567,534 shares; 2019 - 131,812,173 shares, Outstanding: 2020 - 124,217,590 shares; 2019 - 123,000,307 shares	1	1
Capital in excess of par value	391	305
Treasury stock (common), at cost: 2020 - 9,349,944 shares; 2019 - 8,811,866 shares	(674)	(643)
Accumulated other comprehensive loss	(494)	(465)
Retained earnings	3,764	5,133
Shareholders' Equity Total	2,988	4,331
Total Liabilities and Shareholders' Equity	$ 14,046	12,993
Common stock, shares authorized	400,000,000
Common stock, par value	$ 0.01
Air Traffic Liability
Current Liabilities
Air traffic liability	$ 1,073	900
Mileage Plan Revenue [Member]
Current Liabilities
Air traffic liability	$ 733	$ 750

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).