Net Earnings Per Common Unitholders' Interest Net Earnings (Loss) Per Common Unitholders' Interest (Narrative) (Details) - USD ($) |
6 Months Ended | |
|---|---|---|
Jan. 31, 2016 |
Jan. 31, 2015 |
|
| Earnings Per Share [Abstract] | ||
| Dilutive effect on earnings per share | $ 0 | $ 0 |