Concentration of Credit Risk (Tables)

12 Months Ended

Jul. 27, 2013

Risks and Uncertainties [Abstract]

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

AT&T Inc. ("AT&T"), CenturyLink, Inc. ("CenturyLink"), 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 fiscal 2013, 2012, or 2011 as reflected in the following table:

	Fiscal Year Ended
	2013	2012	2011
AT&T	15.5%	13.7%	21.1%
CenturyLink	14.6%	13.6%	10.8%
Comcast	10.9%	12.6%	14.3%
Verizon	9.6%	11.3%	8.9%

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 July 27, 2013 or July 28, 2012 had the following outstanding balances and the related percentage of the Company’s total outstanding balances:

	July 27, 2013				July 28, 2012
	Amount		% of Total		Amount		% of Total
			(Dollars in millions)
CenturyLink	$	62.6	13.7	%	$	47.6	17.7	%
Windstream Corporation	$	59.4	13.0	%	$	35.4	13.2	%
AT&T	$	57.4	12.6	%	$	24.7	9.2	%
Verizon	$	33.4	7.3	%	$	30.5	11.3	%