Details about Accumulated Other Comprehensive Income Components (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
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	$ (65)	[1],[2]	$ 42	[1],[2]	$ 17	[1],[2]
Miscellaneous, Net
Accumulated Other Comprehensive Income (Loss) [Line Items]
Available for sale securities-reclassifications of gains into earnings	(6)	[1]
Fuel Oil Contract | Cash Flow Hedging | Aircraft Fuel
Accumulated Other Comprehensive Income (Loss) [Line Items]
Fuel contracts-reclassifications of (gains) losses into earnings	$ 89	[1]	$ (18)	[1]	$ 141	[1]

[1] Income tax expense for these items was offset by the Company's valuation allowance.

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