Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events (Details)

v3.8.0.1
Subsequent Events (Details)
1 Months Ended 3 Months Ended
Apr. 26, 2018
USD ($)
Mar. 31, 2018
MMBTU
$ / bbl
$ / MMBTU
bbl
Apr. 30, 2018
MMBTU
$ / bbl
$ / MMBTU
bbl
Mar. 31, 2018
USD ($)
$ / bbl
$ / MMBTU
Mar. 31, 2017
USD ($)
May 31, 2018
USD ($)
Jan. 31, 2018
USD ($)
Dec. 31, 2017
Subsequent Event [Line Items]                
Payments for equity method investments | $       $ 1,569,000 $ 10,673,000      
Stock repurchase program, amount authorized to acquire | $             $ 100,000,000  
Strike Force Midstream LLC                
Subsequent Event [Line Items]                
Equity method investment, ownership interest, percent   25.00%   25.00%       25.00%
Payments for equity method investments | $         $ 10,000,000      
NYMEX Henry Hub Swap - 2018                
Subsequent Event [Line Items]                
Daily volume (in MMBtu) | MMBTU   927,000            
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU   3.02   3.02        
NYMEX Henry Hub Swap - 2019                
Subsequent Event [Line Items]                
Daily volume (in MMBtu) | MMBTU   647,000            
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU   2.84   2.84        
NYMEX WTI Swap - 2019                
Subsequent Event [Line Items]                
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl   57.62   57.62        
Daily volume (in Bbls) | bbl   3,000            
Mont Belvieu C3 Swap - 2019                
Subsequent Event [Line Items]                
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl   27.05   27.05        
Daily volume (in Bbls) | bbl   1,000            
NYMEX Henry Hub Swap - 2020                
Subsequent Event [Line Items]                
Daily volume (in MMBtu) | MMBTU   45,000            
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU   2.77   2.77        
Subsequent event | Strike Force Midstream LLC                
Subsequent Event [Line Items]                
Payments for equity method investments | $ $ 175,000,000              
Subsequent event | NYMEX Henry Hub Swap - 2018                
Subsequent Event [Line Items]                
Daily volume (in MMBtu) | MMBTU     53,000          
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU     2.84          
Subsequent event | NYMEX Henry Hub Swap - 2019                
Subsequent Event [Line Items]                
Daily volume (in MMBtu) | MMBTU     15,000          
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU     2.76          
Subsequent event | NYMEX WTI Swap - 2019                
Subsequent Event [Line Items]                
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl     60.24          
Daily volume (in Bbls) | bbl     1,000          
Subsequent event | Mont Belvieu C3 Swap - 2019                
Subsequent Event [Line Items]                
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl     28.04          
Daily volume (in Bbls) | bbl     2,000          
Subsequent event | Mont Belvieu C5 Swap - 2019                
Subsequent Event [Line Items]                
Weighted average price (in usd per MMBtu or Bbl) | $ / bbl     54.08          
Daily volume (in Bbls) | bbl     500          
Subsequent event | NYMEX Henry Hub Swap - 2020                
Subsequent Event [Line Items]                
Daily volume (in MMBtu) | MMBTU     5,000          
Weighted average price (in usd per MMBtu or Bbl) | $ / MMBTU     2.76          
Minimum | Subsequent event                
Subsequent Event [Line Items]                
Stock repurchase program, amount authorized to acquire | $           $ 100,000,000    
Maximum | Subsequent event                
Subsequent Event [Line Items]                
Stock repurchase program, amount authorized to acquire | $           $ 200,000,000