Quarterly report pursuant to Section 13 or 15(d)

Derivative Instrument and Hedging Transactions (Realized gain (loss)) (Details)

v3.4.0.3
Derivative Instrument and Hedging Transactions (Realized gain (loss)) (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Mar. 31, 2016
Mar. 31, 2015
Derivative [Line Items]        
Realized loss on future commodity contracts, net $ 2,730 $ (10,309) $ (14,278) $ (44,831)
Futures Commodity And Forwards Contracts And Open Purchase And Sale Commitments [Member]        
Derivative [Line Items]        
Unrealized gain (loss) on open future commodity and forward contracts and open sale and purchase commitments, net (5,262) (12,866) (8,482) (2,582)
Commodity Contract        
Derivative [Line Items]        
Realized loss on future commodity contracts, net $ 7,992 $ 2,557 $ (5,796) $ (42,249)