Customer Concentration and Revenue Information - Revenue Concentration Risk (Details) - USD ($) $ in Thousands	3 Months Ended
	May 01, 2021	Apr. 25, 2020
Concentration Risk
Contract revenues	$ 727,497	$ 814,322
% of Total	100.00%	100.00%
Revenue Benchmark | Customer Concentration Risk
Concentration Risk
% of Total	10.00%
Revenue Benchmark | Customer Concentration Risk | Five Unnamed Customers
Concentration Risk
% of Total	68.20%	78.50%
Revenue Benchmark | Customer Concentration Risk | Verizon Communications Inc.
Concentration Risk
Contract revenues	$ 91,500	$ 176,100
% of Total	12.60%	21.60%
Revenue Benchmark | Customer Concentration Risk | Lumen Technologies(1)
Concentration Risk
Contract revenues	$ 85,800	$ 148,800
% of Total	11.80%	18.30%
Revenue Benchmark | Customer Concentration Risk | ATT [Member]
Concentration Risk
Contract revenues	$ 155,600	$ 154,000
% of Total	21.40%	18.90%
Revenue Benchmark | Customer Concentration Risk | Comcast [Member]
Concentration Risk
Contract revenues	$ 131,100	$ 118,000
% of Total	18.00%	14.50%
Revenue Benchmark | Customer Concentration Risk | Total other customers combined
Concentration Risk
Contract revenues	$ 263,500	$ 217,400
% of Total	36.20%	26.70%