Supplemental Financial Information - Accrued Liabilities (Details) - USD ($) $ in Millions		Dec. 31, 2015		Dec. 31, 2014
Supplemental Financial Data [Line Items]
Profitsharing and savings plans		$ 655		$ 374
Aircraft and other lease related obligations		74		159
Vacation pay		309		292
Accrued Union Bonuses		329	[1]	9
Health		86		84
Workers compensation		187		165
Property and other taxes		62		81
Other		246		227
Accrued liabilities		2,591		1,565
Fuel derivatives | Accrued Liabilities
Supplemental Financial Data [Line Items]
Derivative Contracts	[2]	$ 643		$ 174

[1] As part of the ongoing negotiations with various union contract groups during 2015, the Company has recorded a liability for estimated bonuses that would be paid out to union members upon ratification of labor agreements. The liability excludes certain immaterial benefit costs that are included as a component of Accounts payable. The amount accrued is subject to change based on subsequent negotiations, and any changes would be recorded on a prospective basis.

[2] The net amounts of derivative assets and liabilities are reconciled to the individual line item amounts presented in the Consolidated Balance Sheet in Note 5.