CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current Assets
Cash and cash equivalents	$ 51	$ 107
Marketable securities	1,261	1,110
Total cash and marketable securities	1,312	1,217
Receivables - net	187	259
Inventories and supplies - net	52	58
Deferred income taxes	123	117
Prepaid expenses and other current assets	102	105
Total Current Assets	1,776	1,756
Property and Equipment
Aircraft and other flight equipment	5,204	5,165
Other property and equipment	899	896
Deposits for future flight equipment	778	555
Property and Equipment Total	6,881	6,616
Less accumulated depreciation and amortization	2,384	2,317
Total Property and Equipment - Net	4,497	4,299
Other Assets	137	126
Total Assets	6,410	6,181
Current Liabilities
Accounts payable	57	62
Accrued wages, vacation and payroll taxes	160	232
Other accrued liabilities	731	629
Air traffic liability	814	631
Current portion of long-term debt	118	117
Total Current Liabilities	1,880	1,671
Long-Term Debt, Net of Current Portion	650	686
Other Liabilities and Credits
Deferred income taxes	753	750
Deferred revenue	382	374
Obligation for pension and postretirement medical benefits	247	246
Other liabilities	332	327
Other Liabilities and Credits Totals	1,714	1,697
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: 200,000,000 shares, Issued: 2015 - 130,551,503 shares; 2014 - 131,556,573 shares, Outstanding: 2015 - 130,444,006 shares; 2014 - 131,481,473	1	1
Capital in excess of par value	211	296
Treasury stock (common), at cost: 2015 - 107,497 shares; 2014 - 75,100 shares	(7)	(4)
Accumulated other comprehensive loss	(305)	(310)
Retained earnings	2,266	2,144
Total Shareholders' Equity	2,166	2,127
Total Liabilities and Shareholders' Equity	$ 6,410	$ 6,181