Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

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, 2017 and 2016:



		Year ended December 31, 2017				Year ended December 31, 2016
(in millions)	Weighted-average useful life (in years)	Gross carrying amount		Accumulated amortization		Gross carrying amount		Accumulated Amortization
Customer relationships/marketing agreements	10	$	27	$	23	$	38	$	32
Owned domestic slots (a)	Indefinite	295		n/a		295		n/a
Gate leasehold rights (a)	15	180		66		180		55
Total	14	$	502	$	89	$	513	$	87

(a) Intangible assets primarily consist of acquired leasehold rights to certain airport owned gates, takeoff and landing slots (a "slot" is the right of an air carrier, pursuant to regulations of the FAA, to operate a takeoff or landing at a specific time at certain airports) at certain domestic slot-controlled airports, and certain intangible assets acquired.

Schedule of New Accounting Principles - Chase Agreement

The estimated impacts on revenue and earnings associated with the Agreement and the resulting required change in accounting methodology recognized subsequent to the effective date of July 1, 2015, are as follows:



(in millions, except per share amounts)	Year ended December 31, 2017			Year ended December 31, 2016			Year ended December 31, 2015
Passenger revenue	$	(364	)	$	(250	)	$	(89	)
Special revenue adjustment	—			—			172
Other revenue	908			794			344
Operating revenues	$	544		$	544		$	427
Net income	$	496		$	293		$	227
Net income per basic share	$	0.82		$	0.47		$	0.34
Net income per diluted share	$	0.82		$	0.46		$	0.34

Schedule of Change in Accounting Estimate

The impacts on expense and earnings from the accelerated depreciation were as follows:



(in millions, except per share amounts)	Year ended December 31, 2017			Year ended December 31, 2016
Depreciation and amortization expense	$	21		$	123
Net income *	$	(19	)	$	(66	)
Net income per basic share	$	(0.03	)	$	(0.11	)
Net income per diluted share	$	(0.03	)	$	(0.10	)

* net of profitsharing benefit