Fair Value Measurements (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands		Apr. 27, 2018	Jul. 28, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	[1]	$ 93,446	$ 82,524
Interest rate swap asset (see Note 5)		5,968	32
Deferred compensation plan assets	[2]	31,784	31,196
Total assets at fair value		131,198	113,752
Interest rate swap liability (see Note 5)		37	6,880
Total liabilities at fair value		37	6,880
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	[1]	93,446	82,524
Interest rate swap asset (see Note 5)		0	0
Deferred compensation plan assets	[2]	31,784	31,196
Total assets at fair value		125,230	113,720
Interest rate swap liability (see Note 5)		0	0
Total liabilities at fair value		0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	[1]	0	0
Interest rate swap asset (see Note 5)		5,968	32
Deferred compensation plan assets	[2]	0	0
Total assets at fair value		5,968	32
Interest rate swap liability (see Note 5)		37	6,880
Total liabilities at fair value		37	6,880
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	[1]	0	0
Interest rate swap asset (see Note 5)		0	0
Deferred compensation plan assets	[2]	0	0
Total assets at fair value		0	0
Interest rate swap liability (see Note 5)		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.