CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE OPERATIONS (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net Income	$ 289	$ 163	$ 430	$ 272
Related to marketable securities:
Unrealized holding gains (losses) arising during the period	4	5	(8)	10
Reclassification adjustment for (gains) losses included in net income	0	(2)	(2)	(5)
Income tax effect	(1)	(1)	4	(2)
Marketable securities, net of tax	3	2	(6)	3
Related to employee benefit plans:
Reclassification of (gains) losses into net income (within Wages and benefits)	11	10	32	30
Income tax effect	(5)	(4)	(12)	(11)
Employee benefit plans, net of tax	6	6	20	19
Related to interest rate derivative instruments:
Unrealized holding gains (losses) arising during the period	(1)	(4)	9	(9)
Reclassification of (gains) losses into net income (within Aircraft rent)	1	2	4	4
Income tax effect	1	1	(5)	(1)
Interest rate derivative instruments, net of tax	1	(1)	8	(6)
Other comprehensive income	10	7	22	16
Comprehensive income	$ 299	$ 170	$ 452	$ 288