Accounts Receivable, Contract Assets, and Contract Liabilities - Customer Credit Concentration (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Apr. 30, 2022	Oct. 30, 2021	Jan. 29, 2022
Concentration Risk
Amount	$ 994,951		$ 895,898
Customer Concentration Risk | Trade Accounts Receivable and Costs and Estimated Earnings | Lumen Technologies
Concentration Risk
Amount	$ 193,000		166,000
% of Total	19.10%	18.40%
Customer Concentration Risk | Trade Accounts Receivable and Costs and Estimated Earnings | Verizon Communications Inc.
Concentration Risk
Amount	$ 148,200		144,300
% of Total	14.70%	16.00%
Customer Concentration Risk | Trade Accounts Receivable and Costs and Estimated Earnings | AT&T Inc.
Concentration Risk
Amount	$ 140,000		106,000
% of Total	13.80%	11.70%
Customer Concentration Risk | Trade Accounts Receivable and Costs and Estimated Earnings | Comcast Corporation
Concentration Risk
Amount	$ 125,700		$ 113,500
% of Total	12.40%	12.60%