Customer Concentration and Revenue Information - Revenue Concentration Risk (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2022	May 01, 2021
Concentration Risk
Contract revenues	$ 876,300	$ 727,497
Revenue Benchmark | Customer Concentration Risk
Concentration Risk
Contract revenues	$ 876,300	$ 727,500
% of Total	100.00%	100.00%
Revenue Benchmark | Customer Concentration Risk | AT&T Inc.
Concentration Risk
Contract revenues	$ 237,400	$ 155,600
% of Total	27.10%	21.40%
Revenue Benchmark | Customer Concentration Risk | Comcast Corporation
Concentration Risk
Contract revenues	$ 111,300	$ 131,100
% of Total	12.70%	18.00%
Revenue Benchmark | Customer Concentration Risk | Lumen Technologies
Concentration Risk
Contract revenues	$ 102,800	$ 85,800
% of Total	11.70%	11.80%
Revenue Benchmark | Customer Concentration Risk | Verizon Communications Inc.
Concentration Risk
Contract revenues	$ 81,000	$ 91,500
% of Total	9.20%	12.60%
Revenue Benchmark | Customer Concentration Risk | Total other customers combined
Concentration Risk
Contract revenues	$ 343,800	$ 263,500
% of Total	39.30%	36.20%