Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2015

Accounting Policies [Abstract]

Schedule of Finite Lived Intangible Assets

The following table is a summary of the Company’s intangible assets, which are included as a component of Other assets in the Company's Consolidated Balance Sheet, as of December 31, 2015 and 2014:

		Year ended December 31, 2015				Year ended December 31, 2014
(in millions)	Weighted-average useful life (in years)	Gross carrying amount		Accumulated amortization		Gross carrying amount		Accumulated Amortization
Customer relationships/marketing agreements	9	$	38	$	30	$	38	$	26
Trademarks/trade names	6	36		34		36		30
Owned domestic slots	Indefinite	303		n/a		303		n/a
Leased domestic slots (b)	47	17		3		19		5
Gate leasehold rights (a)	15	180		43		60		32
Total	15	$	574	$	110	$	456	$	93

(a) Intangible assets primarily consist of acquired leasehold rights to certain airport owned gates at Chicago’s Midway International Airport, takeoff and landing slots (a “slot” is the right of an air carrier, pursuant to regulations of the Federal Aviation Administration (“FAA”), to operate a takeoff or landing at a specific time at certain airports) at certain domestic slot-controlled airports, and certain intangible assets recognized from the AirTran acquisition. The increase in Intangible assets during 2015 was primarily due to the acquisition of two additional airport gate rights at Dallas Love Field, which were subleased from United Airlines. The purchase price paid for these airport gate rights was included as a component of Capital expenditures in the accompanying Consolidated Statement of Cash Flows.

(b) Useful life of leased slots is based on the stated lease term.

Schedule of New Accounting Principles - Chase Agreement

The estimated impacts on revenue and earnings from this change in accounting principle are as follows:

(in millions, except per share amounts)	Year ended December 31, 2015
Passenger revenue	$	(89	)
Special revenue adjustment	172
Other revenue	344
Operating revenues	$	427
Net income	$	227
Net income per basic share	$	0.34
Net income per diluted share	$	0.34

Schedule of Change in Accounting Estimate [Table Text Block]

This change in estimate was recorded on a prospective basis, as of October 1, 2014, the impacts on revenue and earnings are as follows:

(in millions, except per share amounts)	Year ended December 31, 2015		Year ended December 31, 2014
Passenger revenue	$	115	$	55
Net income	$	61	$	29
Net income per basic share	$	0.09	$	0.04
Net income per diluted share	$	0.09	$	0.04