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Commitments and Contingencies Concentration Risk (Details) - Unionized Employees Concentration Risk	12 Months Ended
	Dec. 31, 2020
Flight Attendants
Concentration Risk [Line Items]
Concentration Risk, Percentage	36.10%
Pilots
Concentration Risk [Line Items]
Concentration Risk, Percentage	23.20%
Flight Dispatchers
Concentration Risk [Line Items]
Concentration Risk, Percentage	1.10%
Total Percentage of Employees
Concentration Risk [Line Items]
Concentration Risk, Percentage	60.30%

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
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