Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Schedule of Fair Value Measured On Recurring Basis (Details)

v3.7.0.1
Fair Value Measurements - Schedule of Fair Value Measured On Recurring Basis (Details) - Recurring - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Fair value measurements    
Derivative financial instruments - assets $ 8,521  
Derivative financial instruments - liabilities (16,948) $ (13,470)
Total Derivative Assets (Liabilities) (8,427) (13,470)
Level 1    
Fair value measurements    
Derivative financial instruments - assets 0  
Derivative financial instruments - liabilities 0 0
Total Derivative Assets (Liabilities) 0 0
Level 2    
Fair value measurements    
Derivative financial instruments - assets 8,521  
Derivative financial instruments - liabilities (16,948) (13,470)
Total Derivative Assets (Liabilities) (8,427) (13,470)
Level 3    
Fair value measurements    
Derivative financial instruments - assets 0  
Derivative financial instruments - liabilities 0 0
Total Derivative Assets (Liabilities) $ 0 $ 0