Fair Value Measurements (Unobservable inputs in Level 3 Valuations of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) (Weighted Average [Member], Significant Unobservable Inputs (Level 3) [Member], Fair Value, Measurements, Recurring [Member])	9 Months Ended
	Mar. 31, 2012
Assets [Member] | Commodity Derivative Contracts [Member]
Basis	15.10%
Transportation cost	9.70%
Assets [Member] | Inventories Component [Member]
Basis	10.50%
Transportation cost	6.20%
Liabilities [Member] | Commodity Derivative Contracts [Member]
Basis	24.10%
Transportation cost	12.10%
Liabilities [Member] | Inventories Component [Member]
Basis	4.80%
Transportation cost	9.10%