Quarterly report pursuant to Section 13 or 15(d)

Fair Value (Details Textual)

v3.4.0.3
Fair Value (Details Textual)
Bcf / d in Billions
3 Months Ended
Mar. 31, 2016
USD ($)
Bcf / d
Mar. 31, 2015
USD ($)
Mar. 30, 2016
USD ($)
Feb. 29, 2016
USD ($)
Dec. 31, 2015
Dec. 20, 2012
USD ($)
Schedule of Equity Method Investments [Line Items]            
Transfers between levels $ 0          
Unrealized gain on other equity securities 43,000 $ 0        
Investment warrants $ 0          
Escrow Receivable Release Percentage after Time Expiration 50.00%          
Foreclosure of Black Bison [Member]            
Schedule of Equity Method Investments [Line Items]            
Net assets and liabilities       $ 2,000,000    
Fair value of assets held-for-sale $ 1,800,000          
Fair value of liabilities held-for-sale $ 439,000          
Lightfoot Capital Partners LP [Member]            
Schedule of Equity Method Investments [Line Items]            
Equity interest percentage 6.60%       1.50%  
Minimum [Member] | Lightfoot Capital Partners LP [Member]            
Schedule of Equity Method Investments [Line Items]            
Fair Value Inputs, Discount for Lack of Marketability 12.50% 16.60%        
Fair Value Inputs, Discount Rate 15.00% 12.00%        
Maximum [Member] | Lightfoot Capital Partners LP [Member]            
Schedule of Equity Method Investments [Line Items]            
Fair Value Inputs, Discount for Lack of Marketability 13.90% 21.30%        
Fair Value Inputs, Discount Rate 17.00% 14.00%        
Cash Flow Hedging [Member]            
Schedule of Equity Method Investments [Line Items]            
Cash flow hedge terminated     $ 26,300,000      
Secured Debt [Member] | Key Bank [Member]            
Schedule of Equity Method Investments [Line Items]            
Maximum borrowing capacity           $ 70,000,000
Lightfoot Capital Partners LP [Member]            
Schedule of Equity Method Investments [Line Items]            
Receiving, Storage and Regasification Terminal, In Volume Per Day | Bcf / d 1.5          
Lightfoot Capital Partners LP [Member] | Arc Logistics Partners LP [Member]            
Schedule of Equity Method Investments [Line Items]            
Limited partner interest 40.00%