Quarterly report pursuant to Section 13 or 15(d)

Discontinued Operations (Adjusted carrying amounts of the major classes of assets and liabilities) (Details)

v3.6.0.2
Discontinued Operations (Adjusted carrying amounts of the major classes of assets and liabilities) (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Aug. 11, 2016
Aug. 01, 2016
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Jun. 30, 2016
Disposal Group, Including Discontinued Operation, Liabilities [Abstract]              
Contribution to equity from preferred stockholder   $ 9,900          
Gain on disposal of discontinued operations, net of tax     $ 0 $ 0 $ 1,069 $ 0  
CO2 Business              
Disposal Group, Including Discontinued Operation, Liabilities [Abstract]              
Contribution to equity from preferred stockholder   9,892          
Gain on disposal of discontinued operations, net of tax            
Weald Basin              
Disposal Group, Including Discontinued Operation, Liabilities [Abstract]              
Contribution to equity from preferred stockholder            
Gain on disposal of discontinued operations, net of tax 1,069            
Discontinued Operations, Held-for-sale              
Disposal Group, Including Discontinued Operation, Assets, Current [Abstract]              
Cash 0           $ 141
Accounts receivable 198           249
Inventories 537           533
Other classes of current assets that are not major 38           34
Disposal Group, Including Discontinued Operation, Assets, Noncurrent [Abstract]              
Property and equipment, net 25,089           24,753
Other classes of assets that are not major 204           332
Total assets of the disposal groups 26,066           26,042
Disposal Group, Including Discontinued Operation, Liabilities [Abstract]              
Accounts payable 2,117           2,264
Note payable 5,500           5,500
Asset retirement obligations 2,818           2,818
Other classes of liabilities that are not major 55           56
Total liabilities of the disposal groups 10,490           10,638
Discontinued Operations, Held-for-sale | CO2 Business              
Disposal Group, Including Discontinued Operation, Assets, Current [Abstract]              
Cash   0         141
Accounts receivable   198         249
Inventories   242         232
Other classes of current assets that are not major   38         34
Disposal Group, Including Discontinued Operation, Assets, Noncurrent [Abstract]              
Property and equipment, net   24,294         23,941
Other classes of assets that are not major   204         332
Total assets of the disposal groups   24,976         24,929
Disposal Group, Including Discontinued Operation, Liabilities [Abstract]              
Accounts payable   1,469         1,594
Note payable   5,500         5,500
Asset retirement obligations   2,818         2,818
Other classes of liabilities that are not major   55         56
Total liabilities of the disposal groups   9,842         9,968
Secured promissory note forgiven   625          
Cash received   900          
Stock of UKOG received   0          
Total consideration   25,026          
Discontinued Operations, Held-for-sale | CO2 Business | Series A Preferred Stock              
Disposal Group, Including Discontinued Operation, Liabilities [Abstract]              
Series A Preferred Stock exchanged   $ 23,501          
Discontinued Operations, Held-for-sale | Weald Basin              
Disposal Group, Including Discontinued Operation, Assets, Current [Abstract]              
Cash 0           0
Accounts receivable 0           0
Inventories 295           301
Other classes of current assets that are not major 0           0
Disposal Group, Including Discontinued Operation, Assets, Noncurrent [Abstract]              
Property and equipment, net 795           812
Other classes of assets that are not major 0           0
Total assets of the disposal groups 1,090           1,113
Disposal Group, Including Discontinued Operation, Liabilities [Abstract]              
Accounts payable 648           670
Note payable 0           0
Asset retirement obligations 0           0
Other classes of liabilities that are not major 0           0
Total liabilities of the disposal groups 648           $ 670
Secured promissory note forgiven 0            
Cash received 586            
Stock of UKOG received 925            
Total consideration 1,511            
Discontinued Operations, Held-for-sale | Weald Basin | Series A Preferred Stock              
Disposal Group, Including Discontinued Operation, Liabilities [Abstract]              
Series A Preferred Stock exchanged $ 0