Acquisitions - Additional Information (Narrative) (Details) (USD $)
 12 Months Ended 0 Months Ended 12 Months Ended 0 Months Ended 3 Months Ended
Dec. 31, 2014
Aircraft
May 02, 2013
Dec. 31, 2013
Aircraft
Sep. 03, 2013
Aircraft
Sep. 30, 2014
Business Acquisition [Line Items]          
Number Of Aircraft Purchased 2        
Customer Relationships (EHI)          
Business Acquisition [Line Items]          
Acquisition completion date   May 02, 2013      
Goodwill   $ 231,600,000      
Goodwill and intangible assets   251,300,000      
Acquired goodwill amortization period   15 years      
Acquisition and integration related expenses 1,100,000   8,900,000    
Number Of Aircraft Purchased     28    
Customer Relationships 19,300,000   19,300,000    
Consideration transferred   298,000,000      
Customer Relationships (EHI) | Customer Relationships          
Business Acquisition [Line Items]          
Acquired customer relationship amortized     19,300,000    
Acquired customer relationships amortization period     9 years    
Customer Relationships (EHI) | Trademarks and Trade Names          
Business Acquisition [Line Items]          
Acquired customer relationship amortized     400,000    
Acquired customer relationships amortization period     6 months    
Customer Relationships (Air Amazonia)          
Business Acquisition [Line Items]          
Acquisition completion date       Sep. 03, 2013  
Acquisition and integration related expenses 500,000   1,500,000    
Number Of Aircraft Purchased     6 6  
Purchase price in cash       23,000,000  
Additional purchase price       3,000,000  
Customer Relationships 2,500,000   2,500,000    
Consideration transferred         26,000,000
Customer Relationships (Air Amazonia) | Goodwill          
Business Acquisition [Line Items]          
Goodwill         5,300,000
Customer Relationships (Air Amazonia) | Other Current Assets          
Business Acquisition [Line Items]          
Goodwill         $ 1,000,000