CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities:
Net Income	$ 316	$ 245	$ 251
Adjustments to reconcile net income to net cash provided by operating activities:
Fleet transition and restructuring related charges	0	39	13
Depreciation and amortization	264	247	230
Stock-based compensation and other	10	17	9
Changes in certain assets and liabilities:
Changes in fair values of open fuel hedge contracts	43	14	(14)
Changes in deferred income taxes	94	145	145
Increase (decrease) in air traffic liability	45	67	56
Increase (decrease) in deferred revenue	33	7	(32)
Increase (decrease) in other long-term liabilities	4	70	29
Pension contribution	(114)	(141)	(151)
Other - net	58	(14)	17
Net cash provided by operating activities	753	696	553
Property and equipment additions:
Aircraft and aircraft purchase deposits	(455)	(318)	(139)
Other flight equipment	(24)	(35)	(27)
Other property and equipment	(39)	(34)	(19)
Total property and equipment additions	(518)	(387)	(185)
Assets constructed for others (Terminal 6 at LAX)	(56)	(109)	(29)
Purchases of marketable securities	(1,130)	(884)	(1,022)
Sales and maturities of marketable securities	1,048	956	931
Proceeds from disposition of assets and changes in restricted deposits	11	21	10
Net cash used in investing activities	(645)	(403)	(295)
Cash flows from financing activities:
Proceeds from issuance of long-term debt	0	107	0
Proceeds from sale-leaseback transactions, net	49	0	0
Long-term debt payments	(275)	(334)	(321)
Common stock repurchases	(60)	(80)	(45)
Proceeds and tax benefit from issuance of common stock	31	19	37
Terminal 6 at LAX reimbursement	178	4	0
Other financing activities	(11)	3	(3)
Net cash used in financing activities	(88)	(281)	(332)
Net increase (decrease) in cash and cash equivalents	20	12	(74)
Cash and cash equivalents at beginning of year	102	90	164
Cash and cash equivalents at end of year	122	102	90
Cash paid during the year for:
Interest (net of amount capitalized)	46	74	106
Income taxes	78	8	0
Non-cash transactions:
Relocation credit and assets constructed related to Terminal 6 at LAX	$ 0	$ 16	$ 7