CONSOLIDATED STATEMENTS OF COMPREHENSIVE OPERATIONS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net Income	$ 848	$ 605	$ 508
Related to marketable securities:
Unrealized holding gains (losses) arising during the period	(6)	2	(9)
Reclassification of (gains) losses into Other-net nonoperating income (expense)	1	(2)	(2)
Income tax benefit (expense)	2	0	4
Marketable securities, net of tax	(3)	0	(7)
Related to employee benefit plans:
Actuarial gains/(losses) related to pension and other post retirement benefit plans	10	(210)	358
Reclassification of net pension expense into Wages and benefits	14	9	42
Income tax benefit (expense)	(14)	76	(150)
Employee benefit plans, net of tax	10	(125)	250
Related to interest rate derivative instruments:
Unrealized holding gains (losses) arising during the period	(5)	(8)	10
Reclassification of (gains) losses into Aircraft rent	6	6	6
Income tax benefit (expense)	(1)	0	(6)
Interest rate derivative instruments, net of tax	0	(2)	10
Other comprehensive loss	7	(127)	253
Comprehensive income	$ 855	$ 478	$ 761