Income Taxes (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
DEFERRED TAX LIABILITIES:
Accelerated depreciation	$ 4,069	$ 3,939
Fuel derivative instruments	36	33
Other	84	70
Total deferred tax liabilities	4,189	4,042
DEFERRED TAX ASSETS:
Fuel derivative instruments	8	40
Deferred gains from sale and leaseback of aircraft	24	24
Capital and operating leases	163	179
Deferred tax assets construction obligation	168	127
Accrued engine maintenance	90	84
Accrued employee benefits	307	281
State taxes	74	77
Business partner income	457	339
Net operating losses and credit carryforwards	14	83
Other	118	170
Total deferred tax assets	1,423	1,404
Net deferred tax liability	2,766	2,638
CURRENT:
Federal	355	(45)	4
State	44	12	13
Total current	399	(33)	17
DEFERRED:
Federal	62	287	122
State	(6)	10	6
Total deferred	56	297	128
Total	455	264	145
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Tax at statutory U.S. tax rates	423	240	114
Nondeductible items	10	10	13
State income taxes, net of federal benefit	25	14	13
Other, net	(3)	0	5
Unrecognized Tax Benefits	5
Federal net operating loss carryforwards	34
Effective income tax rate, continuing operations	35.00%
Deferred Tax Assets, Operating Loss Carryforwards	$ 12