Quarterly report pursuant to Section 13 or 15(d)

Fair Value (Details)

v3.5.0.2
Fair Value (Details)
Bcf / d in Billions
3 Months Ended 6 Months Ended
Jun. 30, 2016
USD ($)
Jun. 30, 2015
USD ($)
Jun. 30, 2016
USD ($)
Bcf / d
Jun. 30, 2015
USD ($)
Mar. 30, 2016
USD ($)
Dec. 31, 2015
Dec. 20, 2012
USD ($)
Schedule of Equity Method Investments [Line Items]              
Unrealized gain on other equity securities $ 0 $ 282,000 $ 43,000 $ 282,000      
Lightfoot Capital Partners LP [Member]              
Schedule of Equity Method Investments [Line Items]              
Equity interest percentage 6.60%   6.60%     1.50%  
Minimum [Member] | Lightfoot Capital Partners LP [Member]              
Schedule of Equity Method Investments [Line Items]              
Discount percentage for lack of marketability     7.90% 16.60%      
Discount rate percentage     15.00% 12.00%      
Maximum [Member] | Lightfoot Capital Partners LP [Member]              
Schedule of Equity Method Investments [Line Items]              
Discount percentage for lack of marketability     8.90% 21.30%      
Discount rate percentage     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 and regasification terminal, volume per day (bcf/d) | 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%