Annual report pursuant to Section 13 and 15(d)

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

v3.10.0.1
Fair Value Measurements (Fair Value of Assets and Liabilities Measured on Recurring Basis) (Details) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Assets    
Fair value of derivatives $ 65,114 $ 406
Liabilities    
Fair value of derivatives (17,920) (29,028)
Total net assets (liabilities) 47,194 (28,622)
Level 1    
Assets    
Fair value of derivatives 0 0
Liabilities    
Fair value of derivatives 0 0
Total net assets (liabilities) 0 0
Level 2    
Assets    
Fair value of derivatives 65,114 406
Liabilities    
Fair value of derivatives (17,920) (29,028)
Total net assets (liabilities) 47,194 (28,622)
Level 3    
Assets    
Fair value of derivatives 0 0
Liabilities    
Fair value of derivatives 0 0
Total net assets (liabilities) $ 0 $ 0