Annual report pursuant to Section 13 and 15(d)

LONG-TERM DEBT - Narrative (Details)

v3.7.0.1
LONG-TERM DEBT - Narrative (Details) - USD ($)
 12 Months Ended
Dec. 20, 2015
Dec. 01, 2015
Mar. 31, 2014
Dec. 07, 2012
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 23, 2010
Nov. 24, 2010
Debt Instrument [Line Items]                  
Outstanding borrowings         $ 236,376,000 $ 275,194,000      
Gain on debt extinguishment         518,000 1,617,000 $ 0    
Long-term debt issuance costs         (886,000) $ (71,000) $ (2,446,000)    
Write off of debt issuance cost         $ 500,000        
7.750% Senior Notes (excluding unamortized discount) | Senior Unsecured Notes Due December 15, 2022                  
Debt Instrument [Line Items]                  
Face amount       $ 200,000,000.0          
Stated interest rate       7.75% 7.75% 7.75%      
Proceeds from issuance of long-term debt       $ 191,900,000          
Outstanding borrowings       200,000,000.0          
Debt obligations         $ 5,000,000 $ 50,200,000      
Redemption price (in dollars per share)         86.63        
Repayments of debt         4,500,000 47,900,000      
Accrued interest paid         200,000 1,000,000      
Gain on debt extinguishment         500,000 1,600,000      
Promissory notes                  
Debt Instrument [Line Items]                  
Outstanding borrowings         $ 23,166,000 24,968,000      
Promissory notes | Promissory Note to Purchase Heavy Helicopter                  
Debt Instrument [Line Items]                  
Face amount               $ 27,000,000.0  
Outstanding borrowings $ 19,000,000                
Debt instrument, interest rate at year-end         2.47%        
Note required monthly payments 100,000                
Note required final payment $ 12,800,000                
Promissory notes | Promissory Note to Purchase Medium Helicopter                  
Debt Instrument [Line Items]                  
Face amount                 $ 11,700,000.0
Outstanding borrowings   $ 5,900,000              
Debt instrument, interest rate at year-end         2.43%        
Note required monthly payments   100,000.0              
Note required final payment   $ 4,000,000              
Senior secured revolving credit facility                  
Debt Instrument [Line Items]                  
Line of credit facility, maximum borrowing capacity     $ 200,000,000.0   $ 200,000,000.0        
Maximum commitment increase amount     100,000,000.0            
Commitment fee percent         0.50%        
Remaining borrowing capacity         $ 120,200,000        
Letters of credit outstanding         $ 1,200,000        
Long-term debt issuance costs     (2,400,000)            
Senior secured revolving credit facility | Promissory notes                  
Debt Instrument [Line Items]                  
Repayments of borrowings outstanding       $ 190,000,000          
Letter of Credit                  
Debt Instrument [Line Items]                  
Line of credit facility, maximum borrowing capacity     $ 50,000,000.0            
Base Rate | Senior secured revolving credit facility                  
Debt Instrument [Line Items]                  
Basis spread on variable rate         1.25%        
London Interbank Offered Rate (LIBOR) | Promissory notes | Promissory Note to Purchase Heavy Helicopter                  
Debt Instrument [Line Items]                  
Basis spread on variable rate 1.81%                
London Interbank Offered Rate (LIBOR) | Promissory notes | Promissory Note to Purchase Medium Helicopter                  
Debt Instrument [Line Items]                  
Basis spread on variable rate   1.81%              
London Interbank Offered Rate (LIBOR) | Senior secured revolving credit facility                  
Debt Instrument [Line Items]                  
Basis spread on variable rate         2.25%        
Minimum | 7.750% Senior Notes (excluding unamortized discount) | Senior Unsecured Notes Due December 15, 2022                  
Debt Instrument [Line Items]                  
Redemption price (in dollars per share)           79.00      
Minimum | Senior secured revolving credit facility                  
Debt Instrument [Line Items]                  
Commitment fee percent         0.375%        
Minimum | Base Rate | Senior secured revolving credit facility                  
Debt Instrument [Line Items]                  
Basis spread on variable rate         0.75%        
Minimum | London Interbank Offered Rate (LIBOR) | Senior secured revolving credit facility                  
Debt Instrument [Line Items]                  
Basis spread on variable rate         1.75%        
Maximum | 7.750% Senior Notes (excluding unamortized discount) | Senior Unsecured Notes Due December 15, 2022                  
Debt Instrument [Line Items]                  
Redemption price (in dollars per share)           $ 97.50      
Maximum | Senior secured revolving credit facility                  
Debt Instrument [Line Items]                  
Commitment fee percent         0.50%        
Maximum | Base Rate | Senior secured revolving credit facility                  
Debt Instrument [Line Items]                  
Basis spread on variable rate         2.00%        
Maximum | London Interbank Offered Rate (LIBOR) | Senior secured revolving credit facility                  
Debt Instrument [Line Items]                  
Basis spread on variable rate         3.00%        
Brazil | Other litigation matters                  
Debt Instrument [Line Items]                  
Installment payments         $ 3,400,000