REVENUE (Tables)

12 Months Ended

Dec. 31, 2021

Revenue from Contract with Customer [Abstract]

Disaggregation of Passenger Revenue

The following table provides the components of Passenger revenue recognized for the years ended December 31, 2021, 2020, and 2019:

	Year ended December 31,
(in millions)	2021		2020		2019
Passenger non-loyalty	$	11,377	$	6,303	$	17,578
Passenger loyalty - air transportation	2,136		1,003		2,487
Passenger ancillary sold separately	553		359		711
Total passenger revenues	$	14,066	$	7,665	$	20,776

Rollforward of Air Traffic Liability

As of the years ended December 31, 2021 and 2020, the components of Air traffic liability, including contract liabilities based on tickets sold and unused flight credits available to the Customer, both of which are net of recorded breakage, and loyalty points available for redemption, within the Consolidated Balance Sheet were as follows:

	Balance as of
(in millions)	December 31, 2021		December 31, 2020
Air traffic liability - passenger travel and ancillary passenger services	$	2,936	$	2,686
Air traffic liability - loyalty program	4,789		4,447
Total Air traffic liability	$	7,725	$	7,133

Rollforwards of the Company's Air traffic liability - loyalty program for the years ended December 31, 2021 and 2020 were as follows (in millions):

	Year ended December 31,
	2021		2020
Air traffic liability - loyalty program - beginning balance	$	4,447	$	3,385
Amounts deferred associated with points awarded	2,523		1,958
Revenue recognized from points redeemed - Passenger	(2,136)		(1,003)
Revenue recognized from points redeemed - Other	(45)		(60)
Unused funds converted to loyalty points	—		167
Air traffic liability - loyalty program - ending balance	$	4,789	$	4,447

Air traffic liability includes consideration received for ticket and loyalty related performance obligations which have not been satisfied as of a given date. Rollforwards of the amounts included in Air traffic liability as of December 31, 2021 and 2020 were as follows (in millions):

	Air traffic liability
Balance at December 31, 2020	$	7,133
Current period sales (passenger travel, ancillary services, flight loyalty, and partner loyalty)	14,702
Revenue from amounts included in contract liability opening balances	(2,945)
Revenue from current period sales	(11,165)
Balance at December 31, 2021	$	7,725

	Air traffic liability
Balance at December 31, 2019	$	5,510
Current period sales (passenger travel, ancillary services, flight loyalty, and partner loyalty)	9,348
Revenue from amounts included in contract liability opening balances	(2,317)
Revenue from current period sales	(5,408)
Balance at December 31, 2020	$	7,133