Condensed Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Cash Provided by Operating Activities	$ 1,636	$ 951
Cash Flows From Investing Activities:
Flight equipment, including advance payments	(451)	(514)
Ground property and equipment, including technology	(135)	(100)
Purchase of short-term investments	(344)	(240)
Redemption of short-term investments	115	251
Other, net	3	40
Net cash used in investing activities	(812)	(563)
Cash Flows From Financing Activities:
Payments on long-term debt and capital lease obligations	(301)	(412)
Repurchase of common stock	(425)	(125)
Cash dividends	(75)	(51)
Proceeds from long-term obligations	41	59
Other, net	(30)	(4)
Net cash used in financing activities	(790)	(533)
Net Increase (Decrease) in Cash and Cash Equivalents	34	(145)
Cash and cash equivalents at beginning of period	2,088	2,844
Cash and cash equivalents at end of period	2,122	2,699
Non-Cash Transactions:
Flight equipment under capital leases	$ 39	$ 10