Airport Redevelopment	12 Months Ended
Airport Redevelopment	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Airport Redevelopment	AIRPORT REDEVELOPMENT New York-JFK Airport In 2015, we completed our redevelopment project at New York-JFK's Terminal 4 to facilitate convenient connections for our passengers and improve coordination with our SkyTeam alliance partners. Terminal 4 is operated by JFK International Air Terminal LLC ("IAT"), a private party, under its lease with the Port Authority of New York and New Jersey ("Port Authority"). In December 2010, we entered into a 33-year agreement with IAT ("Sublease") to sublease space in Terminal 4. Also, in 2010, the Port Authority issued approximately $800 million principal amount of special project bonds to fund the majority of the project. We managed the project and bore the construction risk, including cost overruns. We recorded an asset for project costs (e.g., design, permitting, labor and other general construction costs), regardless of funding source, and a construction obligation equal to project costs funded by parties other than us. Our rental payments reduce the construction obligation and result in the recording of interest expense, calculated using the effective interest method. As of December 31, 2017, we have recorded $691 million as property and equipment and $744 million as the related construction obligation. We have an equity method investment in the entity which owns IAT, our sublessor at Terminal 4. The Sublease requires us to pay certain fixed management fees. We determined the investment is a variable interest entity and assessed whether we have a controlling financial interest in IAT. Our rights under the Sublease, with respect to management of Terminal 4, are consistent with rights granted to an anchor tenant under a standard airport lease. Accordingly, we do not consolidate the entity in which we have an investment in our Consolidated Financial Statements. Los Angeles International Airport During 2016, we announced plans to modernize, upgrade and connect Terminals 2 and 3 at Los Angeles International Airport (“LAX”) over the next seven years. A substantial majority of the project costs will be funded through the Regional Airports Improvement Corporation ("RAIC"), a California public benefit corporation, using an $800 million revolving credit facility provided by a group of lenders. The credit facility was executed during 2017. We have guaranteed the obligations of the RAIC under the credit facility. Because the RAIC remains in compliance with the terms of its credit facility, we have not recorded a liability on our Consolidated Balance Sheet as of December 31, 2017. New York-LaGuardia Airport As part of the terminal redevelopment project at LaGuardia Airport, we are partnering with the Port Authority of New York and New Jersey (the “Port Authority”) to replace Terminals C and D with a new state-of-the-art terminal facility consisting of 37 gates across four concourses connected to a central headhouse. The terminal will feature a new, larger Delta Sky Club, wider concourses, more gate seating and 30 percent more concessions space than the existing terminals. The facility will also offer direct access between the parking garage and terminal with improved roadways and drop-off/pick-up areas. The design of the new terminal will integrate sustainable technologies and improved energy efficiency. Construction will be phased to limit passenger inconvenience and is expected to be completed by 2026. In connection with the redevelopment, during 2017, we entered into an amended and restated terminal lease with the Port Authority with a term through 2050. Pursuant to the lease agreement we will (1) fund (through debt issuance and existing cash) and undertake the design, management and construction of the terminal and certain off-premises supporting facilities, (2) receive a Port Authority contribution of $600 million to facilitate construction of the terminal and other supporting infrastructure, (3) be responsible for all operations and maintenance during the term of the lease and (4) have preferential rights to all gates in the terminal subject to Port Authority requirements with respect to accommodation of designated carriers.