Net Earnings (Loss) Per Common Unitholders' Interest (Schedule of Earnings Per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
Apr. 30, 2018	Apr. 30, 2017	Apr. 30, 2018	Apr. 30, 2017
Common unitholders' interest in net earnings	$ 10,752	$ 6,470	$ (38,508)	$ 1,545
Weighted average common units outstanding - diluted	97,152,700	97,152,700	97,152,700	97,255,400
Basic and diluted net earnings per common unitholders' interest	$ 0.11	$ 0.07	$ (0.40)	$ 0.02

The amount of net income or loss for the period per each limited partnership and general partnership unit in instances when basic and diluted earnings per unit are the same amount and aggregated on the face of the financial statements. Basic earnings per unit is the amount of net income or loss for the period per unit outstanding during the reporting period. Diluted earnings per unit includes the amount of net income or loss for the period available to each limited and general partnership unit outstanding during the reporting period and to each unit that would have been outstanding assuming the issuance of units for all dilutive potential units outstanding during the reporting period.

No definition available.

Name:	us-gaap_NetIncomeLossPerOutstandingLimitedPartnershipAndGeneralPartnershipUnitBasicAndDiluted
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration