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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Summary of Significant Accounting Policies - Concentrations of Risk (Details) - employeeGroup	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Total operating expenses \| Aircraft fuel expenditure concentration risk \| Fuel Costs
Concentration Risk [Line Items]
Concentration of risk	28.00%	19.00%	30.00%
Number of employees, total \| Unionized employees concentration risk
Concentration Risk [Line Items]
Concentration of risk	81.00%
Union-represented employee groups	5