Condensed Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Cash Provided by (Used in) Operating Activities	$ 1,004	$ 831
Net Cash Provided by (Used in) Investing Activities [Abstract]
Flight Equipment, Including Advance Payments	(527)	(308)
Ground Property and Equipment, Including Technology	(120)	(99)
Purchase of Investments	(240)	(240)
Redemption of Investments	286	266
Other Investing Activities, Net	(29)	32
Net Cash Used in Investing Activities	(630)	(349)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Payments of Long-term Debt and Capital Lease Obligations	(299)	(367)
Fuel Card Obligation, net	149	171
Other Financing Activities	(4)	(32)
Net Cash Used in Financing Activities	(154)	(228)
Net Increase in Cash and Cash Equivalents	220	254
Cash and cash equivalents	2,416	2,657
Cash and cash equivalents	2,636	2,911
Other Noncash Investing and Financing Items [Abstract]
SkyMiles Used Pursuant to Advance Purchase Under American Express Agreements	83	83
Build-to-Suit Leased Facilities	$ 45	$ 75