Details about Accumulated Other Comprehensive Income Components (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Salaries And Related Costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of unrecognized (gains) losses and prior service cost (credit)	[1]	$ 8	$ (16)	$ 25	$ (50)
Miscellaneous, Net
Accumulated Other Comprehensive Income (Loss) [Line Items]
Available for sale securities-reclassifications of gains into earnings			$ (2)	(1)	(8)
Fuel Oil Contract | Cash Flow Hedging | Aircraft Fuel
Accumulated Other Comprehensive Income (Loss) [Line Items]
Fuel contracts-reclassifications of (gains) losses into earnings		$ 150		$ 429	$ 4

[1] This AOCI component is included in the computation of net periodic pension and other postretirement costs (see Note 5 of this report for additional information).