CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current Assets
Cash and cash equivalents	$ 90	$ 80
Marketable securities	1,330	1,250
Total cash and marketable securities	1,420	1,330
Receivables - net	212	152
Inventories and supplies - net	58	60
Deferred income taxes	120	113
Prepaid expenses and other current assets	124	107
Total Current Assets	1,934	1,762
Property and Equipment
Aircraft and other flight equipment	4,855	4,677
Other property and equipment	853	838
Deposits for future flight equipment	360	446
Property and Equipment Total	6,068	5,961
Less accumulated depreciation and amortization	2,138	2,068
Total Property and Equipment - Net	3,930	3,893
Other Assets	197	183
Total Assets	6,061	5,838
Current Liabilities
Accounts payable	75	64
Accrued wages, vacation and payroll taxes	146	211
Other accrued liabilities	672	624
Air traffic liability	749	564
Current portion of long-term debt	113	117
Total Current Liabilities	1,755	1,580
Long-Term Debt, Net of Current Portion	721	754
Other Liabilities and Credits
Deferred income taxes	725	709
Deferred revenue	334	335
Obligation for pension and postretirement medical benefits	122	123
Other liabilities	309	308
Other Liabilities and Credits Totals	1,490	1,475
Commitments and Contingencies
Shareholders' Equity
Preferred stock, $1 par value Authorized: 5,000,000 shares, none issued or outstanding	0	0
Common stock, $1 par value, Authorized: 100,000,000 shares, Issued: 2014 - 68,798,330 shares; 2013 - 68,766,691 shares, Outstanding: 2014 - 68,788,557; 2013 - 68,745,953	69	69
Capital in excess of par value	524	538
Treasury stock (common), at cost: 2014 - 9,773 shares; 2013 - 20,738 shares	(1)	(2)
Accumulated other comprehensive (loss)	(181)	(183)
Retained earnings	1,684	1,607
Total Shareholders' Equity	2,095	2,029
Total Liabilities and Shareholders' Equity	$ 6,061	$ 5,838