Concentration of Credit Risk (Tables)

6 Months Ended

Jan. 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

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 or six months endedJanuary 26, 2013 or January 28, 2012 as reflected in the following table:

	For the Three Months Ended		For the Six Months Ended
	January 26, 2013	January 28, 2012	January 26, 2013	January 28, 2012
CenturyLink	14.7%	14.5%	14.2%	13.9%
AT&T	13.6%	13.5%	13.5%	14.4%
Comcast	11.0%	12.5%	11.8%	12.7%
Verizon	9.1%	9.9%	9.6%	11.0%

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 January 26, 2013 or July 28, 2012 had the following outstanding balances and the related percentage of the Company’s total outstanding balances:

	January 26, 2013				July 28, 2012
	Amount		% of Total		Amount		% of Total
			(Dollars in millions)
Windstream Corporation	$	54.0	14.3	%	$	35.4	13.2	%
CenturyLink	$	48.1	12.8	%	$	47.6	17.7	%
Verizon	$	26.6	7.1	%	$	30.5	11.3	%