Revenue (Tables)

3 Months Ended

Mar. 31, 2019

Revenue from Contract with Customer [Abstract]

Disaggregation of Passenger Revenue

The following table provides the components of Passenger revenue recognized for the three months ended March 31, 2019 and 2018:

	Three months ended March 31,
(in millions)	2019		2018
Passenger non-loyalty	$	4,043	$	3,948
Passenger loyalty - air transportation	535		491
Passenger ancillary sold separately	167		146
Total passenger revenues	$	4,745	$	4,585

Components of Air Traffic Liability

Rollforwards of the Company's Air traffic liability - loyalty program for the three months ended March 31, 2019 and 2018 were as follows (in millions):

	Three months ended March 31,
	2019			2018
Air traffic liability - loyalty program - beginning balance	$	3,011		$	2,667
Amounts deferred associated with points awarded	711			634
Revenue recognized from points redeemed - Passenger	(535		)	(491		)
Revenue recognized from points redeemed - Other	(16		)	(11		)
Air traffic liability - loyalty program - ending balance	$	3,171		$	2,799

As of March 31, 2019, and December 31, 2018, the components of Air traffic liability, including contract liabilities based on tickets sold, unused funds available to the Customer, and loyalty points available for redemption, net of expected spoilage, within the unaudited Condensed Consolidated Balance Sheet were as follows:

	Balance as of
(in millions)	March 31, 2019		December 31, 2018
Air traffic liability - passenger travel and ancillary passenger services	$	2,843	$	2,059
Air traffic liability - loyalty program	3,171		3,011
Total Air traffic liability	$	6,014	$	5,070

Rollforward of Air Traffic Liability

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 March 31, 2019 and 2018 were as follows (in millions):

	Air traffic liability
Balance at December 31, 2018	$	5,070
Current period sales (passenger travel, ancillary services, flight loyalty, and partner loyalty)	5,704
Revenue from amounts included in contract liability opening balances	(2,008		)
Revenue from current period sales	(2,752		)
Balance at March 31, 2019	$	6,014

	Air traffic liability
Balance at December 31, 2017	$	4,565
Current period sales (passenger travel, ancillary services, flight loyalty, and partner loyalty)	5,407
Revenue from amounts included in contract liability opening balances	(1,831		)
Revenue from current period sales	(2,711		)
Balance at March 31, 2018	$	5,430