Quarterly report pursuant to Section 13 or 15(d)

Equity Investments (Narrative) (Details)

v3.5.0.2
Equity Investments (Narrative) (Details)
a in Thousands
 1 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended
Oct. 19, 2016
Jan. 28, 2014
USD ($)
Mar. 31, 2015
USD ($)
Sep. 30, 2016
USD ($)
Mar. 31, 2016
USD ($)
Sep. 30, 2015
USD ($)
Mar. 31, 2015
USD ($)
Sep. 30, 2016
USD ($)
a
shares
Sep. 30, 2015
USD ($)
Dec. 31, 2014
USD ($)
Oct. 18, 2016
Feb. 01, 2016
USD ($)
Dec. 31, 2012
Oct. 05, 2012
USD ($)
Schedule of Equity Method Investments [Line Items]                            
(Income) loss from equity method investments       $ (5,997,000)   $ 61,891,000   $ 25,576,000 $ 57,036,000          
Distributions from equity method investments               14,220,000 4,761,000          
Payments for equity method investments               $ 18,510,000 13,837,000          
Investment in Tatex Thailand II, LLC                            
Schedule of Equity Method Investments [Line Items]                            
Equity shares owned by affiliate (shares) | shares               85,122            
Total shares owned of subaffiliate (shares) | shares               1,000,000            
Gas and oil area, reserve (acres) | a               243            
(Income) loss from equity method investments       $ (253,000)   0   $ (412,000) 189,000          
Ownership interest, percent       23.50%       23.50%            
Investment in Tatex Thailand III, LLC                            
Schedule of Equity Method Investments [Line Items]                            
Gas and oil area, reserve (acres) | a               245            
(Income) loss from equity method investments       $ 0   0   $ 0 0          
Ownership interest, percent       17.90%       17.90%            
Investment in 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       $ 363,000   58,653,000   $ 24,811,000 71,289,000          
Impairment of oil and gas properties         $ 23,100,000                  
Equity method investment, amount of cash calls, based on proportionate ownership interest               14,500,000            
Equity method investments, increase (decrease) due to foreign currency translation adjustment       $ (1,400,000)   (11,600,000)   $ 8,300,000 (23,300,000)          
Ownership interest, percent       24.9999%       24.9999%            
Investment in Windsor Midstream LLC                            
Schedule of Equity Method Investments [Line Items]                            
(Income) loss from equity method investments       $ (9,014,000)   (323,000)   $ (12,062,000) (18,229,000)          
Ownership interest, percent       22.50%       22.50%            
Distributions from equity method investments               $ 14,200,000            
Investment in Windsor Midstream LLC | MidMar Gas LLC                            
Schedule of Equity Method Investments [Line Items]                            
Ownership interest, percent                         28.40%  
Coronado Midstream | Investment in Windsor Midstream LLC                            
Schedule of Equity Method Investments [Line Items]                            
Proceeds from sale of interest in partnership unit     $ 600,000,000                      
Gain on sale on investment     $ 81,600,000                      
Investment in Blackhawk Midstream LLC                            
Schedule of Equity Method Investments [Line Items]                            
(Income) loss from equity method investments       $ 0   0   $ 0 (7,217,000)          
Ownership interest, percent       48.50%       48.50%            
Investment in Blackhawk Midstream LLC | Ohio Gathering Company, LLC and Ohio Condensate Company, LLC                            
Schedule of Equity Method Investments [Line Items]                            
Amount put in escrow   $ 14,300,000                        
Proceeds from release of escrow deposits             $ 7,200,000              
Purchase price of sold equity interests   $ 190,000,000                        
Investment in Sturgeon Acquisitions LLC                            
Schedule of Equity Method Investments [Line Items]                            
(Income) loss from equity method investments       $ 112,000   (257,000)   $ 623,000 (1,316,000)          
Ownership interest, percent       25.00%       25.00%            
Payments for equity method investments                   $ 20,700,000        
Investment in Mammoth Energy Partners LP                            
Schedule of Equity Method Investments [Line Items]                            
(Income) loss from equity method investments       $ 2,518,000   3,612,000   $ 11,527,000 11,608,000          
Equity method investments, increase (decrease) due to foreign currency translation adjustment       $ 200,000       $ (1,100,000)            
Ownership interest, percent       30.50%       30.50%   30.50%        
Investment in Strike Force Midstream LLC                            
Schedule of Equity Method Investments [Line Items]                            
(Income) loss from equity method investments       $ (99,000)   $ 0   $ (40,000) $ 0          
Equity method investment, amount of cash calls, based on proportionate ownership interest               $ 4,000,000            
Ownership interest, percent       25.00%       25.00%            
Investment in Strike Force Midstream LLC | Rice Energy Inc                            
Schedule of Equity Method Investments [Line Items]                            
Ownership interest, percent       75.00%       75.00%            
Revolving Credit Facility | Investment in Grizzly Oil Sands ULC                            
Schedule of Equity Method Investments [Line Items]                            
Revolving credit facility                           $ 125,000,000.0
Level 3 | Investment in Grizzly Oil Sands ULC                            
Schedule of Equity Method Investments [Line Items]                            
Equity method investments, fair value of minority interest         $ 39,100,000                  
Level 3 | Investment in Strike Force Midstream LLC                            
Schedule of Equity Method Investments [Line Items]                            
Equity method investments, fair value of minority interest                       $ 22,500,000    
Subsequent event | Investment in Mammoth Energy Partners LP                            
Schedule of Equity Method Investments [Line Items]                            
Ownership interest, percent 24.20%                   30.50%      
Sale of stock, percentage of ownership after transaction 24.20%