CONCENTRATION OF CREDIT RISK (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 28, 2012		Jul. 30, 2011		Jul. 31, 2010
Concentration of Credit Risk [Abstract]
Number of customers classified as highly concentrated	5		5		5
Concentration Risk [Line Items]
Concentration Risk, Percentage (in hundredths)	59.60%		61.90%		66.30%
Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Customer base classified as highly concentrated, Minimum (in hundredths)	10.00%
Customer Concentration Risk [Member] | AT&T [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage (in hundredths)	13.70%		21.10%		20.40%
Customer Concentration Risk [Member] | CenturyLink [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage (in hundredths)	13.60%	[1]	10.80%	[1]	11.60%	[1]
Customer Concentration Risk [Member] | Verizon [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage (in hundredths)	11.30%		8.90%		11.50%
Customer Concentration Risk [Member] | Comcast [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage (in hundredths)	12.60%		14.30%		14.30%
Credit Concentration Risk [Member]
Concentration Risk [Line Items]
Customer base classified as highly concentrated, Minimum (in hundredths)	10.00%
Credit Concentration Risk [Member] | AT&T [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage (in hundredths)	9.20%		12.70%
Accounts receivable and costs and estimated earnings in excess of billings	24.7		29.2
Credit Concentration Risk [Member] | CenturyLink [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage (in hundredths)	17.70%		18.00%
Accounts receivable and costs and estimated earnings in excess of billings	47.6		41.4
Credit Concentration Risk [Member] | Windstream Corporation [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage (in hundredths)	13.20%		8.90%
Accounts receivable and costs and estimated earnings in excess of billings	35.4		20.5
Credit Concentration Risk [Member] | Verizon [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage (in hundredths)	11.30%		11.50%
Accounts receivable and costs and estimated earnings in excess of billings	30.5		26.4

[1] For comparison purposes, revenues from CenturyLink, Inc. and Qwest Communications International, Inc. have been combined for periods prior to their April 2011 merger.