CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Current Assets
Cash and cash equivalents	$ 81	$ 73
Marketable securities	1,526	1,255
Total cash and marketable securities	1,607	1,328
Receivables - net	254	212
Inventories and supplies - net	45	51
Prepaid expenses and other current assets	97	72
Total Current Assets	2,003	1,663
Property and Equipment
Aircraft and other flight equipment	6,198	5,690
Other property and equipment	994	955
Deposits for future flight equipment	551	771
Property and Equipment Total	7,743	7,416
Less accumulated depreciation and amortization	2,784	2,614
Total Property and Equipment - Net	4,959	4,802
Other Assets	73	65
Total Assets	7,035	6,530
Current Liabilities
Accounts payable	78	63
Accrued wages, vacation and payroll taxes	239	298
Air traffic liability	870	669
Other accrued liabilities	757	661
Current portion of long-term debt	117	114
Total Current Liabilities	2,061	1,805
Long-Term Debt, Net of Current Portion	509	569
Other Liabilities and Credits
Deferred income taxes	721	682
Deferred revenue	480	431
Obligation for pension and postretirement medical benefits	271	270
Other liabilities	366	362
Other Liabilities and Credits Totals	1,838	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 - 128,941,102 shares; 2015 - 128,442,099 shares, Outstanding: 2016 - 123,079,519 shares; 2015 - 125,175,325 shares	1	1
Capital in excess of par value	91	73
Treasury stock (common), at cost: 2016 - 5,861,583 shares; 2015 - 3,266,774 shares	(444)	(250)
Accumulated other comprehensive loss	(287)	(303)
Retained earnings	3,266	2,890
Total Shareholders' Equity	2,627	2,411
Total Liabilities and Shareholders' Equity	$ 7,035	$ 6,530