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Summary of Passenger Revenue by Geographic Region and by Mainline Versus Regional (Detail) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2018 | Mar. 31, 2017
Deferred Revenue Arrangement [Line Items] |  |  |
Passenger-Mainline | $ 6,616 | $ 6,227 |
Passenger-Regional | 1,533 | 1,426 |
Total passenger revenue | 8,149 | 7,653 | [1]
International |  |  |
Deferred Revenue Arrangement [Line Items] |  |  |
Total passenger revenue | 3,181 | 3,002 |
Domestic |  |  |
Deferred Revenue Arrangement [Line Items] |  |  |
Passenger-Mainline | 3,485 | 3,272 |
Passenger-Regional | 1,483 | 1,379 |
Total passenger revenue | 4,968 | 4,651 |
Atlantic | International |  |  |
Deferred Revenue Arrangement [Line Items] |  |  |
Total passenger revenue | 1,252 | 1,117 |
Pacific | International |  |  |
Deferred Revenue Arrangement [Line Items] |  |  |
Total passenger revenue | 1,069 | 1,053 |
Latin America | International |  |  |
Deferred Revenue Arrangement [Line Items] |  |  |
Total passenger revenue | $ 860 | $ 832 |
[1] | Amounts adjusted due to the adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) and Accounting Standards Update No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. See Note 1 to the financial statements contained in Part I, Item 1 of this report for additional information.

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