Derivative Instruments and Hedging Activities (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2015	Aug. 01, 2014
Derivative [Line Items]
Company's credit spread (in hundredths)	1.25%	1.50%
Derivatives, Fair Value [Line Items]
Fair value, liability	$ 9,821	$ 7,943
Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Fair value, asset	3,759	240
Fair value, liability	$ 9,821	7,943
Interest Rate Swap [Member] | Interest Rate Swap July 25, 2011 [Member]
Derivative [Line Items]
Trade date	Jul. 25, 2011
Effective date	May 03, 2013
Term	3 years
Notional amount	$ 50,000
Fixed rate (in hundredths)	2.45%
Interest Rate Swap [Member] | Interest Rate Swap December 7, 2011 [Member]
Derivative [Line Items]
Trade date	Dec. 07, 2011
Effective date	May 03, 2013
Term	3 years
Notional amount	$ 50,000
Fixed rate (in hundredths)	1.40%
Interest Rate Swap [Member] | Interest Rate Swap March 18, 2013 [Member]
Derivative [Line Items]
Trade date	Mar. 18, 2013
Effective date	May 03, 2015
Term	3 years
Notional amount	$ 50,000
Fixed rate (in hundredths)	1.51%
Interest Rate Swap [Member] | Interest Rate Swap April 8, 2013 [Member]
Derivative [Line Items]
Trade date	Apr. 08, 2013
Effective date	May 03, 2015
Term	2 years
Notional amount	$ 50,000
Fixed rate (in hundredths)	1.05%
Interest Rate Swap [Member] | Interest Rate Swap April 15, 2013 [Member]
Derivative [Line Items]
Trade date	Apr. 15, 2013
Effective date	May 03, 2015
Term	2 years
Notional amount	$ 50,000
Fixed rate (in hundredths)	1.03%
Interest Rate Swap [Member] | Interest Rate Swap April 22, 2013 [Member]
Derivative [Line Items]
Trade date	Apr. 22, 2013
Effective date	May 03, 2015
Term	3 years
Notional amount	$ 25,000
Fixed rate (in hundredths)	1.30%
Interest Rate Swap [Member] | Interest Rate Swap April 25, 2013 [Member]
Derivative [Line Items]
Trade date	Apr. 25, 2013
Effective date	May 03, 2015
Term	3 years
Notional amount	$ 25,000
Fixed rate (in hundredths)	1.29%
Interest Rate Swap [Member] | Interest Rate Swap June 18, 2014 [Member]
Derivative [Line Items]
Trade date	Jun. 18, 2014
Effective date	May 03, 2015
Term	4 years
Notional amount	$ 40,000
Fixed rate (in hundredths)	2.51%
Increase in notional amount each year	$ 40,000
Maximum notional amount	$ 160,000
Interest Rate Swap [Member] | Interest Rate Swap June 24, 2014 [Member]
Derivative [Line Items]
Trade date	Jun. 24, 2014
Effective date	May 03, 2015
Term	4 years
Notional amount	$ 30,000
Fixed rate (in hundredths)	2.51%
Increase in notional amount each year	$ 30,000
Maximum notional amount	$ 120,000
Interest Rate Swap [Member] | Interest Rate Swap July 1, 2014 [Member]
Derivative [Line Items]
Trade date	Jul. 01, 2014
Effective date	May 05, 2015
Term	4 years
Notional amount	$ 30,000
Fixed rate (in hundredths)	2.43%
Increase in notional amount each year	$ 30,000
Maximum notional amount	$ 120,000
Interest Rate Swap [Member] | Interest Rate Swap One January 30, 2015 [Member]
Derivative [Line Items]
Trade date	Jan. 30, 2015
Effective date	May 03, 2019
Term	2 years
Notional amount	$ 80,000
Fixed rate (in hundredths)	2.15%
Interest Rate Swap [Member] | Interest Rate Swap Two January 30, 2015 [Member]
Derivative [Line Items]
Trade date	Jan. 30, 2015
Effective date	May 03, 2019
Term	2 years
Notional amount	$ 60,000
Fixed rate (in hundredths)	2.16%
Interest Rate Swap [Member] | Interest Rate Swap Three January 30, 2015 [Member]
Derivative [Line Items]
Trade date	Jan. 30, 2015
Effective date	May 04, 2021
Term	3 years
Notional amount	$ 120,000
Fixed rate (in hundredths)	2.41%
Interest Rate Swap [Member] | Interest Rate Swap Four January 30, 2015 [Member]
Derivative [Line Items]
Trade date	Jan. 30, 2015
Effective date	May 03, 2019
Term	2 years
Notional amount	$ 60,000
Fixed rate (in hundredths)	2.15%
Interest Rate Swap [Member] | Interest Rate Swap Five January 30, 2015 [Member]
Derivative [Line Items]
Trade date	Jan. 30, 2015
Effective date	May 04, 2021
Term	3 years
Notional amount	$ 80,000
Fixed rate (in hundredths)	2.40%
Other Assets [Member] | Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Fair value, asset	$ 3,759	240
Current Interest Rate Swap Liability [Member] | Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Fair value, liability	1,117	4,704
Long-term Interest Rate Swap Liability [Member] | Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Fair value, liability	$ 8,704	$ 3,239