Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer, Excluding Assessed Tax	$ 420	$ 1,914	$ 1,973	$ 5,563
Passenger Revenue - Loyalty Air Travel	25	91	153	275
Other Revenue - Loyalty	38	54	127	146
Other Revenue - Non Loyalty	9	27	42	79
Revenue from Contract with Customer, Excluding Assessed Tax	492	2,086	2,295	6,063
Air Traffic Liability - Passenger Travel	1,020		1,020		$ 929
Air Traffic Liability - Loyalty Program (Air Transportation)	703		703		661
Other Deferred Revenue	42		42		10
Contract with Customer, Liability	1,765		1,765		1,600
Contract with Customer, Liability, Revenue Recognized			697	856
Air Traffic Liability	703	$ 647	703	647	$ 661	$ 580
Increase (Decrease) to Air Traffic Liability - Points Redeemed			(153)	(275)
Increase (Decrease) to Air Traffic Liability - Points Earned			195	$ 342
Loyalty points, pre-purchase arrangement			150
Loyalty points, pre-purchase arrangement, carrying value	$ 75		$ 75
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-06-30
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	3 years		3 years

Value of revenue deferred or cost to provide future products or services, primarily air transportation, associated with programs used by airlines to encourage passenger loyalty by providing rewards geared to the frequency of travel on the sponsoring airline, typically in the form of frequent flyer miles, points, or segments that can be accumulated and converted into free or discounted travel or other redemption options.

No definition available.