Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Textuals (Details)

v2.4.0.6
Fair Value Measurements - Textuals (Details)
 12 Months Ended
Jun. 30, 2012
Maximum
  
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]  
Maturity period of cash equivalents 3 months
Nautilus Purchase and Sale Agreement (PSA)
  
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]  
Increase in working interest 3.00%
Time Deposits | Maximum
  
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]  
Maturity period of cash equivalents 90 days