Concentration of Credit Risk (Tables)

3 Months Ended

Oct. 27, 2012

Risks and Uncertainties [Abstract]

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

CenturyLink, Inc. (“CenturyLink”), AT&T Inc. (“AT&T”), Comcast Corporation (“Comcast”), and Verizon Communications, Inc. (“Verizon”) represent a significant portion of the Company’s customer base and each were over 10% of total revenue during the three months endedOctober 27, 2012 or October 29, 2011 as reflected in the following table:

	For the Three Months Ended
	October 27, 2012	October 29, 2011
CenturyLink	13.7%	13.3%
AT&T	13.5%	15.2%
Comcast	12.7%	12.9%
Verizon	10.2%	12.0%

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 27, 2012 or July 28, 2012 had the following outstanding balances and the related percentage of the Company’s total outstanding balances:

	October 27, 2012				July 28, 2012
	Amount		% of Total		Amount		% of Total
			(Dollars in millions)
CenturyLink	$	44.3	16.3	%	$	47.6	17.7	%
Windstream Corporation	$	35.1	12.9	%	$	35.4	13.2	%
AT&T	$	26.4	9.7	%	$	24.7	9.2	%