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Revenue - Summary of Roll Forward of Frequent Flyer Deferred Revenue (Details) - Deferred Revenue for Miles in Loyalty Program - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
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Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017
Movement in Deferred Revenue [Roll Forward] |  |  |  |
Total Frequent flyer deferred revenue - beginning balance | $ 4,937 | $ 4,940 | $ 4,783 | $ 4,889
Total miles awarded | 607 | 531 | 1,210 | 1,019
Travel miles redeemed (Passenger revenue) | (519) | (535) | (928) | (933)
Non-travel miles redeemed (Other operating revenue) | (36) | (45) | (76) | (84)
Total Frequent flyer deferred revenue - ending balance | $ 4,989 | $ 4,891 | $ 4,989 | $ 4,891

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- Definition Frequent flyer mileage miles awarded in period. + References No definition available. + Details
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- Definition Non-travel miles redemption, frequent flyer deferred revenue. + References No definition available. + Details
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Namespace Prefix: | ual_
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- Definition Travel miles redemption, frequent flyer deferred revenue. + References No definition available. + Details
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- Definition Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 605 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 13.A.3) -URI http://asc.fasb.org/extlink&oid=65893310&loc=d3e214044-122780 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 605 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 13.A.4(a).Q1) -URI http://asc.fasb.org/extlink&oid=65893310&loc=d3e214044-122780 + Details
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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- Details
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