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	$ 679	$ 1,025
Cash Flow from Investing Activities:
Capital expenditures, including aircraft lease deposits	(882)	(236)
Net (increase) decrease in short-term investments	(228)	(726)
Net (increase) decrease in restricted cash and short-term investments	(3)	(33)
Proceeds from sale of equipment and property	26	15
Net cash used for investing activities	(1,087)	(980)
Cash Flow from Financing Activities:
Payments on long-term debt and capital lease obligations	(392)	(314)
Funds Transferred To Affiliates Net	0	36
Proceeds from:
Issuance of debt	161	0
Sale leaseback transactions	764	324
Other	0	0
Net cash provided by financing activities	533	46
Net increase (decrease) in cash	125	91
Cash at beginning of period	474	280
Cash at end of period	$ 599	$ 371