Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Fair Value of Assets and Liabilities Measured on Recurring Basis) (Details)

v3.7.0.1
Fair Value Measurements (Fair Value of Assets and Liabilities Measured on Recurring Basis) (Details) - Recurring Basis - USD ($)
$ in Thousands
Jun. 30, 2017
Dec. 31, 2016
Assets    
Derivative financial instruments $ 13,045 $ 103
Liabilities    
Derivative financial instruments (2,684) (18,296)
Net Derivative Fair Value 10,361 (18,193)
Level 1    
Assets    
Derivative financial instruments 0 0
Liabilities    
Derivative financial instruments 0 0
Net Derivative Fair Value 0 0
Level 2    
Assets    
Derivative financial instruments 13,045 103
Liabilities    
Derivative financial instruments (2,684) (18,296)
Net Derivative Fair Value 10,361 (18,193)
Level 3    
Assets    
Derivative financial instruments 0 0
Liabilities    
Derivative financial instruments 0 0
Net Derivative Fair Value $ 0 $ 0