Commitments and Contingencies - Employees (Details) $ in Millions	1 Months Ended		12 Months Ended
	Jul. 31, 2015	Aug. 31, 2014	Dec. 31, 2015 USD ($) employee_group airport	Dec. 31, 2014 USD ($) employee_group
Concentration Risk [Line Items]
Number of airports in which company operates			56
Health Insurance Product Line
Concentration Risk [Line Items]
Accrued health care claims | $			$ 4.3	$ 3.1
International Association of Machinists and Aerospace Workers (IAMAW)
Concentration Risk [Line Items]
Number of airports in which company operates			1
Association of Flight Attendants (AFA-CWA)
Concentration Risk [Line Items]
Tentative collective bargaining agreement, contract term		5 years
Ramp Service Agents [Member]
Concentration Risk [Line Items]
Tentative collective bargaining agreement, contract term	5 years
Unionized employees concentration risk | Number of employees (percent)
Concentration Risk [Line Items]
Union-represented employee groups | employee_group			4	4
Concentration of risk			73.00%	67.00%
Unionized employees concentration risk | Number of employees (percent) | Air Line Pilots Association, International (ALPA)
Concentration Risk [Line Items]
Concentration of risk			26.00%
Unionized employees concentration risk | Number of employees (percent) | Association of Flight Attendants (AFA-CWA)
Concentration Risk [Line Items]
Concentration of risk			43.00%
Unionized employees concentration risk | Number of employees (percent) | Transport Workers Union (TWU)
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%