Quarterly report pursuant to Section 13 or 15(d)

Equity Investments (Narrative) (Details)

v3.10.0.1
Equity Investments (Narrative) (Details)
$ / shares in Units, a in Thousands
 1 Months Ended 3 Months Ended 6 Months Ended
Jun. 29, 2018
USD ($)
shares
May 01, 2018
USD ($)
Jun. 05, 2017
USD ($)
$ / shares
shares
Dec. 31, 2017
USD ($)
Jun. 30, 2018
USD ($)
Jun. 30, 2017
USD ($)
Dec. 31, 2014
entity
Sep. 30, 2014
a
Jun. 30, 2018
USD ($)
a
project
Jun. 30, 2017
USD ($)
Feb. 17, 2017
$ / shares
Dec. 15, 2016
$ / shares
Apr. 30, 2015
bbl
Mar. 31, 2015
Jun. 30, 2014
bbl
Schedule of Equity Method Investments [Line Items]                              
(Income) loss from equity method investments         $ (8,888,000) $ 25,824,000     $ (22,424,000) $ 30,731,000          
Distributions from equity method investments                 1,196,000 1,429,000          
Share price (in dollars per share) | $ / shares                     $ 19.48 $ 20.96      
Gain on sale of equity method investments         122,035,000 12,523,000     122,035,000 12,523,000          
Proceeds from sale of equity method investments                 221,965,000 0          
Payments for equity method investments                 1,569,000 24,151,000          
Tatex Thailand III LLC                              
Schedule of Equity Method Investments [Line Items]                              
Distributions from equity method investments       $ 200,000                      
Tatex Thailand II, LLC                              
Schedule of Equity Method Investments [Line Items]                              
(Income) loss from equity method investments         $ (63,000) (211,000)     $ (104,000) (454,000)          
Equity method investment, ownership interest, percent         23.50%       23.50%            
Grizzly Oil Sands ULC                              
Schedule of Equity Method Investments [Line Items]                              
Gas and oil area, reserve (acres) | a                 830            
(Income) loss from equity method investments         $ 228,000 208,000     $ 558,000 573,000          
Number of oil sand projects | project                 3            
Production volume (in Bbls/day) | bbl                         2,200   11,300
Other than temporary impairment loss                 $ 0 0          
Equity method investment, amount of cash calls, based on proportionate ownership interest                 1,600,000            
Equity method investments, increase (decrease) due to foreign currency translation adjustment         $ (3,400,000) 4,500,000     $ 8,700,000 5,800,000          
Equity method investment, ownership interest, percent         24.9999%       24.9999%            
Timber Wolf Terminals LLC                              
Schedule of Equity Method Investments [Line Items]                              
(Income) loss from equity method investments         $ 534,000 0     $ 536,000 4,000          
Distributions from equity method investments                 $ 400,000            
Equity method investment, ownership interest, percent         50.00%       50.00%            
Windsor Midstream LLC                              
Schedule of Equity Method Investments [Line Items]                              
(Income) loss from equity method investments         $ (9,000) 25,545,000     $ (9,000) 25,234,000          
Distributions from equity method investments                 $ 0 200,000          
Equity method investment, ownership interest, percent         22.50%       22.50%            
Coronado Midstream LLC | Windsor Midstream LLC                              
Schedule of Equity Method Investments [Line Items]                              
Equity method investment, ownership interest, percent                           28.40%  
Sturgeon Acquisitions LLC                              
Schedule of Equity Method Investments [Line Items]                              
(Income) loss from equity method investments         $ 0 (139,000)     $ 0 (71,000)          
Equity method investment, ownership interest, percent         0.00%   25.00%   0.00%            
Gain on sale of equity method investments     $ 12,500,000                        
Mammoth Energy Services LP                              
Schedule of Equity Method Investments [Line Items]                              
Equity method investments, increase (decrease) due to foreign currency translation adjustment         $ (100,000) 20,000     $ (300,000) 100,000          
Equity method investment, ownership interest, percent             30.50%                
Number of entities contributed for ownership interest | entity             4                
Shares received from equity method investee in exchange for ownership interest (in shares) | shares     2,000,000                        
Share price (in dollars per share) | $ / shares     $ 18.50                        
Strike Force Midstream LLC                              
Schedule of Equity Method Investments [Line Items]                              
(Income) loss from equity method investments         $ (336,000) $ (83,000)     (693,000) 2,458,000          
Distributions from equity method investments   $ 175,000,000             $ 800,000 1,200,000          
Equity method investment, ownership interest, percent   25.00%     0.00%       0.00%            
Gain on sale of equity method investments   $ 96,400,000                          
Payments for equity method investments                   $ 23,000,000          
Phu Horm Field | Apico Llc                              
Schedule of Equity Method Investments [Line Items]                              
Gas and oil area, reserve (acres) | a                 180            
Concession Acreage in Southeast Asia | Tatex Thailand III LLC                              
Schedule of Equity Method Investments [Line Items]                              
Gas and oil area, reserve (acres) | a               245              
Apico Llc | Tatex Thailand II, LLC                              
Schedule of Equity Method Investments [Line Items]                              
Ownership percentage         8.50%       8.50%            
Strike Force Midstream LLC | Rice Energy Inc                              
Schedule of Equity Method Investments [Line Items]                              
Ownership percentage by parent       75.00%                      
Over-Allotment Option | Mammoth Energy Services LP                              
Schedule of Equity Method Investments [Line Items]                              
Equity method investment, ownership interest, percent 22.20%                            
Gain on sale of equity method investments $ 25,600,000                            
Proceeds from sale of equity method investments $ 47,000,000                            
Over-Allotment Option | Common Stock | Mammoth Energy Services LP                              
Schedule of Equity Method Investments [Line Items]                              
Number of shares sold (in shares) | shares 1,235,600                            
Shares owned (in shares) | shares 9,948,522