Details about Accumulated Other Comprehensive Income Components (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Salaries And Related Costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of unrecognized (gains) losses and prior service cost and the effect of curtailments and settlements	[1]	$ 26	$ 31	$ (65)
Miscellaneous, Net
Accumulated Other Comprehensive Income (Loss) [Line Items]
Available-for-sale securities - reclassifications of gains into earnings		(1)		(6)
Fuel Oil Contract | Aircraft Fuel
Accumulated Other Comprehensive Income (Loss) [Line Items]
Fuel contracts-reclassifications of losses into earnings		$ 217	$ 604	$ 89

[1] This AOCI component is included in the computation of net periodic pension and other postretirement costs (see Note 8 of this report for additional information).