Concentration of Credit Risk (Tables)

3 Months Ended

Oct. 26, 2013

Risks and Uncertainties [Abstract]

Schedule that Represents A Significant Portion of the Company’s Customer Base and Each Over 10% of Total Revenue

10% of total revenue during the three months endedOctober 26, 2013 or October 27, 2012:

	For the Three Months Ended
	October 26, 2013	October 27, 2012
AT&T Inc. ("AT&T")	17.5%	13.5%
CenturyLink, Inc. ("CenturyLink")	15.5%	13.7%
Comcast Corporation ("Comcast")	10.5%	12.7%
Verizon Communications, Inc. ("Verizon")	8.4%	10.2%

Schedule of Customers Representing 10% or More of Combined Amounts of Trade Accounts Receivable and Costs and Estimated Earnings in Excess of Billings with the Following Outstanding Balances and Related Percentages of the Company’s Total Outstanding Balances

Customers representing 10% or more of combined amounts of trade accounts receivable and costs and estimated earnings in excess of billings as of October 26, 2013 or July 27, 2013 had the following outstanding balances and the related percentage of the Company’s total outstanding balances:

	October 26, 2013				July 27, 2013
	Amount		% of Total		Amount		% of Total
			(Dollars in millions)
AT&T	$	69.0	13.1	%	$	57.4	12.6	%
CenturyLink	$	66.5	12.6	%	$	62.6	13.7	%
Verizon	$	54.8	10.4	%	$	33.4	7.3	%
Windstream Corporation	$	51.4	9.8	%	$	59.4	13.0	%