Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurement - Fair Value of Assets and Liabilities Measured on a Recurring Basis (Details)

v3.19.3
Fair Value Measurement - Fair Value of Assets and Liabilities Measured on a Recurring Basis (Details) - Recurring - USD ($)
$ in Thousands
Sep. 30, 2019
Dec. 31, 2018
Liabilities:    
Total liabilities $ 9,501 $ 6,027
Level 2    
Assets:    
Total assets 208 766
Level 2 | Interest rate swap instruments    
Assets:    
Total assets 41 733
Liabilities:    
Liability derivatives 7,600 3,187
Level 2 | Commodity swap instruments    
Assets:    
Total assets 167 33
Liabilities:    
Liability derivatives 0 70
Level 2 | Interest make-whole provisions    
Liabilities:    
Liability derivatives 873 1,808
Level 3    
Liabilities:    
Contingent revenue earn-out $ 1,028 $ 962