Quarterly report pursuant to Section 13 or 15(d)

Note 8 - Leases (Details Textual)

v3.19.3
Note 8 - Leases (Details Textual)
$ in Thousands
9 Months Ended
Sep. 30, 2019
USD ($)
Sep. 30, 2018
USD ($)
Jan. 01, 2019
USD ($)
Dec. 31, 2018
USD ($)
Number of Operating Leases     1  
Operating Lease, Right-of-Use Asset $ 10,239    
Lessee, Operating Lease, Discount Rate 10.75%      
Short-term Lease, Cost $ 13,300      
Operating Lease, Liability, Total $ 9,760      
Minimum [Member]        
Lessee, Operating Lease, Term of Contract 3 years      
Maximum [Member]        
Lessee, Operating Lease, Term of Contract 20 years      
Pipeline Right-of-way Arrangement [Member]        
Lessee, Operating Lease, Term of Contract 10 years      
Lessee, Operating Lease, Renewal Term 10 years      
Land [Member]        
Lessee, Operating Lease, Renewal Term 5 years      
Houston Office Lease [Member]        
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year $ 800      
Lessee, Operating Lease, Liability, Payments, Due Year Two 1,900      
Lessee, Operating Lease, Liability, Payments, Due Year Three 1,900      
Lessee, Operating Lease, Liability, Payments, Due Year Four 2,000      
Lessee, Operating Lease, Liability, Payments, Due Year Five 500      
Lessee, Operating Lease, Liability, Payments, Due after Year Five 13,200      
Operating Lease, Cost $ 2,000 $ 2,000    
Lessee, Operating Lease, Discount Rate 9.75%      
Accounting Standards Update 2016-02 [Member]        
Operating Lease, Right-of-Use Asset     $ 5,000  
Operating Lease, Liability, Total     $ 5,000