Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2019

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, 2019 and 2018:

		Year ended December 31, 2019				Year ended December 31, 2018
(in millions)	Weighted-average useful life (in years)	Gross carrying amount		Accumulated amortization		Gross carrying amount		Accumulated Amortization
Customer relationships/marketing agreements	12	$	14	$	13	$	27	$	25
Owned domestic slots (a)	Indefinite	295		n/a		295		n/a
Gate leasehold rights (b)	—	—		—		180		78
Total	12	$	309	$	13	$	502	$	103

(a) Intangible assets primarily consist of acquired rights to certain airport owned 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 acquired.

(b) Airport gate leasehold rights are classified as right-of-use assets upon adoption of the New Lease Standard. See Note 7.

Schedule of Change in Accounting Estimate

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

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

* net of profitsharing benefit and income taxes