Commitments and Contingencies - Employees (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	3 Months Ended
	Aug. 31, 2014	Mar. 31, 2015	Dec. 31, 2014	Jul. 08, 2014 employee
Concentration Risk [Line Items]
Number of airports in which entity operates		57
Health Insurance [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Accrued health care claims		3.2	$ 3.1
Ramp Service Agents [Member]
Concentration Risk [Line Items]
Number of employees				250
Association of Flight Attendants [Member]
Concentration Risk [Line Items]
Tentative collective bargaining agreement, contract term	5 years
International Association Of Machinists And Aerospace Workers (IAM) [Member]
Concentration Risk [Line Items]
Number of airports in which entity operates		4
Unionized Employees Concentration Risk [Member] | Number of Employees, Total [Member]
Concentration Risk [Line Items]
Company's employees covered under collective bargaining agreements (as a percent)		70.00%
Unionized Employees Concentration Risk [Member] | Number of Employees, Total [Member] | Air Line Pilots Association, International [Member]
Concentration Risk [Line Items]
Company's employees covered under collective bargaining agreements (as a percent)		26.00%
Unionized Employees Concentration Risk [Member] | Number of Employees, Total [Member] | Association of Flight Attendants [Member]
Concentration Risk [Line Items]
Company's employees covered under collective bargaining agreements (as a percent)		37.00%
Unionized Employees Concentration Risk [Member] | Number of Employees, Total [Member] | Transport Workers Union [Member]
Concentration Risk [Line Items]
Company's employees covered under collective bargaining agreements (as a percent)		1.00%
Unionized Employees Concentration Risk [Member] | Number of Employees, Total [Member] | International Association Of Machinists And Aerospace Workers (IAM) [Member]
Concentration Risk [Line Items]
Company's employees covered under collective bargaining agreements (as a percent)		6.00%