Accounts Receivable - Customer Credit Concentration (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 30, 2021	Jan. 25, 2020	Jan. 26, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 858,123	$ 817,245
% of Total	100.00%	100.00%	100.00%
Verizon Communications Inc. | Trade Accounts Receivable and Costs and Estimated Earnings [Member] | Customer Concentration Risk [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 389,900	$ 440,200
% of Total	37.40%	41.80%
Lumen Technologies | Trade Accounts Receivable and Costs and Estimated Earnings [Member] | Customer Concentration Risk [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 173,500	$ 175,800
% of Total	16.60%	16.70%
Comcast Corporation | Trade Accounts Receivable and Costs and Estimated Earnings [Member] | Customer Concentration Risk [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 131,700	$ 114,000
% of Total	12.60%	10.80%