Nature of Operations and Summary of Significant Accounting Policies (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Inventories
Inventory allowance	11.6	$ 10.1
Aircraft and rotable spares | Maximum
Property and equipment
Depreciable Life	18 years
Residual Value (as a percent)	30.00%
Aircraft and rotable spares | Minimum
Property and equipment
Depreciable Life	10 years
Residual Value (as a percent)	0.00%
Ground equipment
Property and equipment
Residual Value (as a percent)	0.00%
Ground equipment | Maximum
Property and equipment
Depreciable Life	10 years
Ground equipment | Minimum
Property and equipment
Depreciable Life	5 years
Office Equipment
Property and equipment
Residual Value (as a percent)	0.00%
Office Equipment | Maximum
Property and equipment
Depreciable Life	7 years
Office Equipment | Minimum
Property and equipment
Depreciable Life	5 years
Leasehold Improvements
Property and equipment
Residual Value (as a percent)	0.00%
Leasehold Improvements | Maximum
Property and equipment
Depreciable Life	15 years
Building
Property and equipment
Residual Value (as a percent)	0.00%
Building | Maximum
Property and equipment
Depreciable Life	39 years 6 months
Building | Minimum
Property and equipment
Depreciable Life	20 years