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Details about Accumulated Other Comprehensive Income Components (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Salaries And Related Costs |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
Amortization of unrecognized (gains) losses and prior service cost and the effect of curtailments and settlements | [1] | $ 58 | $ 26 | $ 31
Miscellaneous, Net |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
Reclassifications of gains into earnings |  |  | (2) |
Fuel Oil Contract | Aircraft Fuel |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
Reclassifications of losses into earnings | [2] | $ 2 | $ 217 | $ 604
[1] | This AOCI component is included in the computation of net periodic pension and other postretirement costs (see Note 8 of this report for additional information).
[2] | The last of the Company's fuel hedge derivatives designated for cash flow hedge accounting expired in December 2016. The 2017 amount reclassified from AOCI into fuel expense represents hedge losses on December 2016 settled trades, but for which the associated fuel purchased in December 2016 was not consumed until January 2017. The Company's current strategy is to not enter into transactions to hedge its fuel consumption, although the Company regularly reviews its strategy based on market conditions and other factors.

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- Definition Amount, before tax, of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e689-108580 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e637-108580 + Details
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