v2.4.0.8
Commitments, Contingencies, and Concentrations (Details) (USD $)
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Open purchase commitments [Abstract]    
Open purchase commitments $ 194,200,000  
Total number of aircraft to be purchased under purchase commitment 60  
Nonrefundable deposits 18,300,000  
Number of Helicopters | Supplier Concentration Risk, Helicopter Fleet | Airbus Helicopters
   
Concentration Risk [Line Items]    
Concentration risk, percentage (in hundredths) 82.00%  
Number of Helicopters | Supplier Concentration Risk, Helicopter Fleet | Bell Helicopter, Inc.
   
Concentration Risk [Line Items]    
Concentration risk, percentage (in hundredths) 16.00%  
Number of Employees | Labor Force Concentration Risk | Pilots Under Collective Bargaining Agreement
   
Concentration Risk [Line Items]    
Concentration risk, percentage (in hundredths) 28.00%  
Number of Transports | Customer Concentration Risk, Transports | Private insurance carriers
   
Concentration Risk [Line Items]    
Concentration risk, percentage (in hundredths) 33.00% 35.00%
Number of Transports | Customer Concentration Risk, Transports | Medicare
   
Concentration Risk [Line Items]    
Concentration risk, percentage (in hundredths) 33.00% 31.00%
Number of Transports | Customer Concentration Risk, Transports | Medicaid
   
Concentration Risk [Line Items]    
Concentration risk, percentage (in hundredths) 21.00% 21.00%
Number of Transports | Customer Concentration Risk, Transports | Self-pay patients
   
Concentration Risk [Line Items]    
Concentration risk, percentage (in hundredths) 13.00% 13.00%
Revolving Credit Facility Due 2017
   
Letters of Credit [Line Items]    
Number of letters of credit reducing available borrowing capacity under revolving credit facility 3  
Amount of letters of credit reducing available borrowing capacity under revolving credit facility $ 3,525,000