Consolidated Statements of Cash Flow (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Income (Loss)	$ 854	$ 593	$ (1,237)
Depreciation, Depletion and Amortization, Nonproduction	1,523	1,511	1,536
Amortization of Debt Discount (Premium)	193	216	370
Gains (Losses) on Extinguishment of Debt	68	391	83
Derivative, Gain (Loss) on Derivative, Net	135	(136)	(148)
Deferred Income Tax Expense (Benefit)	(2)	9	(329)
Pension and Other Postretirement Benefit Expense	(308)	(301)	307
Share-based Compensation	72	89	108
Restructuring Costs and Asset Impairment Charges	142	182	0
Increase (Decrease) in Receivables	(76)	(141)	147
Increase (Decrease) in Margin Deposits Outstanding	24	0	(1,132)
Increase (Decrease) in Restricted Cash and Investments for Operating Activities	153	16	79
Increase (Decrease) in Prepaid Expense and Other Assets	(16)	(7)	(61)
Increase (Decrease) in Air Traffic Liability	174	232	(286)
Increase (Decrease) in Frequent Flyer Liability	82	(345)	(298)
Increase (Decrease) in Accounts Payable and Accrued Liabilities	303	516	143
Increase (Decrease) in Other Operating Assets and Liabilities, Net	(373)	(98)	(138)
Other Operating Activities, Cash Flow Statement	(66)	105	(29)
Net cash provided by (used in) operating activities	2,834	2,832	1,379
Property and equipment additions:
Payments for Flight Equipment	(907)	(1,055)	(951)
Ground property and equipment, including technology	(347)	(287)	(251)
Payments to Acquire Investments	(1,078)	(815)	0
Proceeds from Sale, Maturity and Collection of Investments	844	149	256
Other, net	(10)	(18)	(62)
Net cash (used in) provided by investing activities	(1,498)	(2,026)	(1,008)
Cash Flows From Financing Activities:
Repayments of Long-term Debt, Long-term Capital Lease Obligations, and Capital Securities	(4,172)	(3,722)	(2,891)
Proceeds From Long-term Obligations	2,395	1,130	2,966
Proceeds from (Repayments of) Lines of Credit	318	0	0
Payments of Debt Issuance Costs	(63)	(19)	0
(Increase) decrease in restricted cash and cash equivalents	(51)	0	0
Other, net	2	90	(94)
Net cash used in financing activities	(1,571)	(2,521)	(19)
Net Increase in Cash and Cash Equivalents	(235)	(1,715)	352
Cash and cash equivalents at beginning of period	2,892	4,607	4,255
Cash and cash equivalents at end of period	2,657	2,892	4,607
Interest Paid	925	1,036	867
Non-cash transactions:
Flight equipment under capital leases	117	329	57
RedevelopmentProjectFundedByThirdParties	126	0	0
Debt relief through vendor negotiations	0	(160)	0
Debt discount on American Express Agreement	0	110	0
Aircraft delivered under seller financing	$ 0	$ 20	$ 139