Special Items - Additional Information (Detail)	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2016 Contract	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) Contract plan	Sep. 30, 2015 USD ($)	Dec. 31, 2014 Attendant	Dec. 31, 2015 USD ($)
Special Charges [Line Items]
Labor agreement costs		$ 14,000,000		$ 124,000,000
Severance and benefits costs		13,000,000	$ 28,000,000	27,000,000	$ 103,000,000
Severance and benefits costs net of tax		8,000,000		17,000,000
Charge related to the amended lease				$ 74,000,000
Lease maturity year				2029
(Gains) losses on sale of assets and other special charges		18,000,000	48,000,000	$ 32,000,000	92,000,000
(Gains) losses on sale of assets and other special charges net of tax		12,000,000		20,000,000
Venezuela local currency loss			61,000,000	8,000,000
Venezuela local currency loss net of tax				5,000,000
Sale of an affiliate				9,000,000
Sale of an affiliate net of tax				6,000,000
Write off of unamortized discount					134,000,000
Accrual severance and benefit		34,000,000	$ 110,000,000	$ 34,000,000	$ 110,000,000
Severance-related accrual expected payment date				2016
Newark Liberty International Airport
Special Charges [Line Items]
Impairment of indefinite-lived intangible assets				$ 412,000,000
Impairment of indefinite-lived intangible assets, net of tax benefits				$ 264,000,000
Flight Attendant Postretirement Medical Plan | Postretirement Medical Plan
Special Charges [Line Items]
Number of plans amended | plan				2
Curtailment gain recognition of prior service credit		47,000,000		$ 47,000,000
Curtailment gain recognition of prior service credit,net of tax				$ 30,000,000
Int'1 Association of Machinists
Special Charges [Line Items]
Number of new contracts extended | Contract	7			7
Service contract extended year	2021			2021
Labor agreement costs		61,000,000		$ 171,000,000
Labor agreement costs net of tax		$ 39,000,000		109,000,000
Lease Amendment Charges
Special Charges [Line Items]
Charge related to the amended lease				74,000,000
Charge related to the amended lease net of tax				$ 47,000,000
Voluntary early out program
Special Charges [Line Items]
Number of positions eliminated | Attendant						2,500
Voluntary early out program | Maximum
Special Charges [Line Items]
Severance payment per participant							$ 100,000