Net Loss Per Common Unitholders' Interest (Details) - USD ($)	3 Months Ended
Oct. 31, 2019	Oct. 31, 2018
Earnings Distribution Allocation [Line Items]
Value of dilutive securities	$ 0	$ 0
Common unitholders' interest in net earnings (loss)	$ (44,891,000)	$ (56,445,000)
Weighted average common units outstanding, basic and diluted	97,152,700	97,152,700
Basic and diluted loss per common unit	$ (0.46)	$ (0.58)
$0.56 to $0.63 \| Common Unitholders [Member]
Earnings Distribution Allocation [Line Items]
Ratio of total distributions payable	51.50%
$0.56 to $0.63 \| General Partner [Member]
Earnings Distribution Allocation [Line Items]
Ratio of total distributions payable	48.50%
$0.64 to $0.82 \| Common Unitholders [Member]
Earnings Distribution Allocation [Line Items]
Ratio of total distributions payable	76.80%
$0.64 to $0.82 \| General Partner [Member]
Earnings Distribution Allocation [Line Items]
Ratio of total distributions payable	23.20%
$0.83 and above \| Common Unitholders [Member]
Earnings Distribution Allocation [Line Items]
Ratio of total distributions payable	86.90%
$0.83 and above \| General Partner [Member]
Earnings Distribution Allocation [Line Items]
Ratio of total distributions payable	13.10%
Minimum [Member] \| $0.56 to $0.63
Earnings Distribution Allocation [Line Items]
Earnings Per Share, Basic, Distributed	$ 0.83
Minimum [Member] \| $0.64 to $0.82
Earnings Distribution Allocation [Line Items]
Earnings Per Share, Basic, Distributed	0.64
Minimum [Member] \| $0.83 and above
Earnings Distribution Allocation [Line Items]
Earnings Per Share, Basic, Distributed	0.56
Maximum [Member] \| $0.64 to $0.82
Earnings Distribution Allocation [Line Items]
Earnings Per Share, Basic, Distributed	0.82
Maximum [Member] \| $0.83 and above
Earnings Distribution Allocation [Line Items]
Earnings Per Share, Basic, Distributed	$ 0.63

The percentage of the total distribution that is allocated to each partner type: General or Limited.

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[Line Items] for Earnings Distribution Allocation [Table]

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Amount of increase (decrease) to net income used for calculating diluted earnings per share (EPS), resulting from the assumed exercise stock options, restrictive stock units (RSUs), convertible preferred stock of an employee stock ownership plan (ESOP), and other dilutive convertible securities.

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Dividends declared in the period and the contractual amount of dividends (or interest on participating income bonds) that must be paid per security.

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Aggregate amount of net income allocated to limited partners.

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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.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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