Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net Income	$ 3,793	$ 3,372	$ 2,972
Other comprehensive income:
Change in amortization of accumulated actuarial losses and prior service costs, net of tax expense of $305 million, tax benefit of $16 million and tax benefit of $125 million, respectively	492	(28)	(200)
Change in fuel hedge mark-to-market, net of tax benefit of $0 million, tax benefit of $7 million and $18 million, respectively	0	(11)	(30)
Change in accumulated other comprehensive income (loss) of equity method investees	(2)	(3)	0
Other Comprehensive Income (Loss), Net of Tax	490	(42)	(230)
Total comprehensive income	$ 4,283	$ 3,330	$ 2,742