CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Current Assets
Cash and cash equivalents	$ 78	$ 73
Marketable securities	1,486	1,255
Total cash and marketable securities	1,564	1,328
Receivables - net	235	212
Inventories and supplies - net	45	51
Prepaid expenses and other current assets	79	72
Total Current Assets	1,923	1,663
Property and Equipment
Aircraft and other flight equipment	5,945	5,690
Other property and equipment	967	955
Deposits for future flight equipment	617	771
Property and Equipment Total	7,529	7,416
Less accumulated depreciation and amortization	2,699	2,614
Total Property and Equipment - Net	4,830	4,802
Other Assets	76	65
Total Assets	6,829	6,530
Current Liabilities
Accounts payable	63	63
Accrued wages, vacation and payroll taxes	213	298
Air traffic liability	868	669
Other accrued liabilities	809	661
Current portion of long-term debt	116	114
Total Current Liabilities	2,069	1,805
Long-Term Debt, Net of Current Portion	531	569
Other Liabilities and Credits
Deferred income taxes	678	682
Deferred revenue	467	431
Obligation for pension and postretirement medical benefits	270	270
Other liabilities	359	362
Other Liabilities and Credits Totals	$ 1,774	$ 1,745
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: 2016 - 128,901,410 shares; 2015 - 128,442,099 shares, Outstanding: 2016 - 123,913,223 shares; 2015 - 125,175,325 shares	1	1
Capital in excess of par value	86	73
Treasury stock (common), at cost: 2016 - 4,988,187 shares; 2015 - 3,266,774 shares	(377)	(250)
Accumulated other comprehensive loss	(294)	(303)
Retained earnings	3,039	2,890
Total Shareholders' Equity	2,455	2,411
Total Liabilities and Shareholders' Equity	$ 6,829	$ 6,530