Consolidated Statements Of Cash Flows (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Statement of Cash Flows [Abstract]
Net Cash Provided by (used for) Operating Activities	$ 683	$ 1,067
Cash Flow from Investing Activities:
Capital expenditures, including aircraft lease deposits	(885)	(238)
Net (increase) decrease in short-term investments	(226)	(726)
Net (increase) decrease in restricted cash and short-term investments	(3)	(33)
Proceeds from sale of equipment and property	26	12
Net cash used for investing activities	(1,088)	(985)
Cash Flow from Financing Activities:
Payments on long-term debt and capital lease obligations	(394)	(314)
Proceeds from:
Issuance of debt	161	0
Sale leaseback transactions	764	324
Other	0	0
Net cash provided by financing activities	531	10
Net increase (decrease) in cash	126	92
Cash at beginning of period	480	283
Cash at end of period	$ 606	$ 375