Customer Concentration and Revenue Information - Customer Type (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 30, 2022	Jul. 31, 2021	Jul. 30, 2022	Jul. 31, 2021
Concentration Risk
Contract revenues	$ 972,273	$ 787,568	$ 1,848,573	$ 1,515,065
Customer Concentration Risk | Revenue Benchmark
Concentration Risk
Contract revenues	$ 972,300	$ 787,600	$ 1,848,600	$ 1,515,100
% of Total	100.00%	100.00%	100.00%	100.00%
% of Total	100.00%	100.00%	100.00%	100.00%
Customer Concentration Risk | Revenue Benchmark | Telecommunications
Concentration Risk
Contract revenues	$ 871,000	$ 697,500	$ 1,649,900	$ 1,337,200
% of Total	89.60%	88.60%	89.30%	88.30%
Customer Concentration Risk | Revenue Benchmark | Underground facility locating
Concentration Risk
Contract revenues	$ 71,400	$ 65,800	$ 142,300	$ 130,700
% of Total	7.30%	8.30%	7.70%	8.60%
Customer Concentration Risk | Revenue Benchmark | Electrical and gas utilities and other
Concentration Risk
Contract revenues	$ 29,900	$ 24,300	$ 56,400	$ 47,200
% of Total	3.10%	3.10%	3.00%	3.10%
Five Unnamed Customers | Customer Concentration Risk | Revenue Benchmark
Concentration Risk
% of Total			67.30%	66.50%