|
Asset Retirement Obligations (Details Textual) (USD $)
In Thousands, unless otherwise specified |
6 Months Ended | 12 Months Ended |
|---|---|---|
|
Oct. 31, 2012
|
Apr. 30, 2012
|
|
| Asset Retirement Obligation [Abstract] | ||
| Expenditures for abandonments | $ 0 | $ 0 |