Quarterly report pursuant to Section 13 or 15(d)

Other Non-Current Assets (Details)

v3.8.0.1
Other Non-Current Assets (Details)
$ in Thousands
 3 Months Ended
Mar. 31, 2018
USD ($)
number_of_renewal_options
Dec. 31, 2017
USD ($)
Operating Leased Assets [Line Items]    
Land lease and purchase options $ 3,166 $ 2,948
Permitting costs 6,719 4,708
Goodwill 1,190 1,190
Other 428 430
Total other non-current assets $ 11,503 $ 9,276
Term of lease (in years) 4 years  
Extension term (in years) 20 years  
Number of renewal terms | number_of_renewal_options 6  
Renewal term (in years) 5 years  
Maximum terms (in years) 60 years  
Minimum    
Operating Leased Assets [Line Items]    
Term of lease (in years) 4 years  
Maximum    
Operating Leased Assets [Line Items]    
Term of lease (in years) 5 years