Condensed Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Cash Provided by (Used in) Operating Activities	$ 1,463	$ 1,774
Net Cash Provided by (Used in) Investing Activities [Abstract]
Payments for Flight Equipment	(609)	(481)
Payments to Acquire Other Productive Assets	(395)	(172)
Payments to Acquire Investments	(479)	(479)
Proceeds from Sale, Maturity and Collection of Investments	514	250
Payments for (Proceeds from) Other Investing Activities	(32)	8
Net Cash Provided by (Used in) Investing Activities	(1,001)	(874)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Repayments of Long-term Debt, Long-term Capital Lease Obligations, and Capital Securities	(741)	(2,394)
Proceeds from Issuance of Long-term Debt	0	1,599
Payments of Debt Issuance Costs	0	(58)
Increase (Decrease) in Restricted Cash	0	84
Proceeds from (Repayments of) Lines of Credit	158	0
Proceeds from (Payments for) Other Financing Activities	3	0
Net Cash Provided by (Used in) Financing Activities	(580)	(937)
Cash and Cash Equivalents, Period Increase (Decrease)	(118)	(37)
Cash and Cash Equivalents, at Carrying Value	2,657	2,892
Cash and Cash Equivalents, at Carrying Value	2,539	2,855
Other Noncash Investing and Financing Items [Abstract]
Other Significant Noncash Transaction, Value of Consideration Given	(167)	0
Other Significant Noncash Transaction, Value of Consideration Received	154	43
Capital Lease Obligations Incurred	$ 0	$ 89