Fair Value Measurements (Details) (USD $) In Thousands	Sep. 30, 2011	Jun. 30, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives Assets	$ 1,064	$ 896
Total assets at fair value	1,064	896
Derivatives Liabilities	20,721	3,330
Total liabilities at fair value	20,721	3,330
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives Assets	0	0
Total assets at fair value	0	0
Derivatives Liabilities	0	0
Total liabilities at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives Assets	1,064	896
Total assets at fair value	1,064	896
Derivatives Liabilities	20,721	3,330
Total liabilities at fair value	20,721	3,330
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives Assets	0	0
Total assets at fair value	0	0
Derivatives Liabilities	0	0
Total liabilities at fair value	$ 0	$ 0