Customer Concentration and Revenue Information - Customer Type (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 30, 2021	Oct. 24, 2020	Oct. 30, 2021	Oct. 24, 2020
Concentration Risk
Contract revenues	$ 853,973	$ 810,256	$ 2,369,038	$ 2,448,500
Customer Concentration Risk | Revenue Benchmark
Concentration Risk
Contract revenues	$ 854,000	$ 810,300	$ 2,369,000	$ 2,448,500
% of Total	100.00%	100.00%	100.00%	100.00%
Customer Concentration Risk | Revenue Benchmark | Telecommunications
Concentration Risk
Contract revenues	$ 757,900	$ 721,200	$ 2,095,100	$ 2,193,900
% of Total	88.80%	89.00%	88.40%	89.60%
Customer Concentration Risk | Revenue Benchmark | Underground facility locating
Concentration Risk
Contract revenues	$ 67,600	$ 59,000	$ 198,200	$ 171,300
% of Total	7.90%	7.30%	8.40%	7.00%
Customer Concentration Risk | Revenue Benchmark | Electrical and gas utilities and other
Concentration Risk
Contract revenues	$ 28,500	$ 30,100	$ 75,700	$ 83,300
% of Total	3.30%	3.70%	3.20%	3.40%
Five Unnamed Customers | Customer Concentration Risk | Revenue Benchmark
Concentration Risk
% of Total			66.00%	75.60%