Collective Bargaining Agreement, Contractual Provision Adjustments

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- Definition

Collective Bargaining Arrangement, Term

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- Definition

Entity Number of Unionized Employee Groups

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- Definition

Ratification Incentive

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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.

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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.

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The amount needed to reflect the estimated ultimate cost of settling claims relating to insured events that have occurred on or before the balance sheet date, whether or not reported to the insurer at that date.

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Commitments and Contingencies - Employees (Details) $ in Millions	1 Months Ended	12 Months Ended
	Feb. 28, 2018	Dec. 31, 2019 USD ($) employee_group	Dec. 31, 2018 USD ($)
Health Insurance Product Line
Concentration Risk [Line Items]
Accrued health care claims		$ 5.2	$ 4.4
Air Line Pilots Association, International (ALPA)
Concentration Risk [Line Items]
Collective bargaining arrangement, term	5 years
Pilots
Concentration Risk [Line Items]
Ratification Incentive			80.2
Collective bargaining agreement, contractual provision adjustments			$ 8.5
Unionized employees concentration risk \| Number of employees (percent)
Concentration Risk [Line Items]
Union-represented employee groups \| employee_group		5
Concentration of risk		81.00%
Unionized employees concentration risk \| Number of employees (percent) \| Air Line Pilots Association, International (ALPA)
Concentration Risk [Line Items]
Concentration of risk		27.00%
Unionized employees concentration risk \| Number of employees (percent) \| Association of Flight Attendants (AFA-CWA)
Concentration Risk [Line Items]
Concentration of risk		47.00%
Unionized employees concentration risk \| Number of employees (percent) \| Professional Airline Flight Control Association (PAFCA)
Concentration Risk [Line Items]
Concentration of risk		1.00%
Unionized employees concentration risk \| Number of employees (percent) \| International Association of Machinists and Aerospace Workers (IAMAW)
Concentration Risk [Line Items]
Concentration of risk		3.00%
Unionized employees concentration risk \| Number of employees (percent) \| Transport Workers Union of America (TWU)
Concentration Risk [Line Items]
Concentration of risk		3.00%