Fair Value Measurements, Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Recurring [Member] - USD ($) $ in Thousands		Apr. 30, 2021	Jul. 31, 2020
Assets and Liabilities Measured at Fair Value on a Recurring Basis [Abstract]
Cash equivalents	[1]	$ 127,001	$ 132,001
Deferred compensation plan assets	[2]	31,519	28,530
Total assets at fair value		158,520	160,531
Interest rate swap liability (see Note 6)		18,442	27,746
Total liabilities at fair value		18,442	27,746
Level 1 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis [Abstract]
Cash equivalents	[1]	127,001	132,001
Interest rate swap liability (see Note 6)		0	0
Total liabilities at fair value		0	0
Level 2 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis [Abstract]
Cash equivalents	[1]	0	0
Interest rate swap liability (see Note 6)		18,442	27,746
Total liabilities at fair value		18,442	27,746
Level 3 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis [Abstract]
Cash equivalents	[1]	0	0
Interest rate swap liability (see Note 6)		0	0
Total liabilities at fair value		$ 0	$ 0

[1] Consists of money market fund investments.

[2] Represents plan assets invested in mutual funds established under a rabbi trust for the Company’s non-qualified savings plan and is included in the Condensed Consolidated Balance Sheets as other assets.