Airport Redevelopment (Details) - USD ($) $ in Millions	12 Months Ended		48 Months Ended
	Dec. 31, 2020	Dec. 31, 2010	Dec. 31, 2020	Dec. 31, 2017
Financial Guarantee | Revolving Credit Facility
Agreements and Obligations [Line Items]
Aggregate commitments guaranteed	$ 800		$ 800
JFK IAT Member LLC
Agreements and Obligations [Line Items]
Lease agreement, term		33 years
Port Authority
Agreements and Obligations [Line Items]
Special project bonds face amount		$ 800
NYTDC
Agreements and Obligations [Line Items]
Special project bonds face amount	611
LAX Redevelopment Project
Agreements and Obligations [Line Items]
Total expected project costs	2,300		2,300
Expected net projects costs	500		500
Project costs reflected as investing cash flows			200
Amount spent on project costs	315
Project costs paid by credit facility	293
Project costs paid by company	22
LAX Redevelopment Project | City of Los Angeles
Agreements and Obligations [Line Items]
Total appropriation to date by city	1,800		1,800
Maximum reimbursement by city	1,800		1,800
LaGuardia Airport Redevelopment Project
Agreements and Obligations [Line Items]
Expected net projects costs	3,500		3,500
Amount spent on project costs	$ 600		$ 1,500
Port Authority contribution to redevelopment project				$ 481