Fair Value Measures Fair Value Measures (Details) - USD ($) $ in Thousands	Jul. 31, 2020	Jul. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 11,483	$ 12,389
Financial and Nonfinancial Liabilities, Fair Value Disclosure	399,698	399,638
Long-term Debt	400,000
Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	11,483	12,389
Cash Equivalents, at Carrying Value	11,483	12,389
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	11,483	12,389
Financial and Nonfinancial Liabilities, Fair Value Disclosure	449,731	411,510
Fixed Rate Debt [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt	399,698	399,638
Fixed Rate Debt [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	$ 449,731	$ 411,510