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Accounts Receivable Concentration Risk (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | 9 Months Ended |
--- | --- | --- | --- | ---
Oct. 27, 2018 | Oct. 28, 2017 | Jan. 27, 2018 | Oct. 27, 2018 | Oct. 28, 2017 | Jan. 28, 2018
Concentration Risk |  |  |  |  |  |
Accounts receivable, net | $ 849,769 |  | $ 318,684 | $ 849,769 |  | $ 630,400
Concentration risk percentage | 100.00% | 100.00% |  | 100.00% | 100.00% |
Customer Concentration Risk | Trade Accounts Receivable and Costs and Estimated Earnings | Comcast Corporation |  |  |  |  |  |
Concentration Risk |  |  |  |  |  |
Accounts receivable, net | $ 166,600 |  | $ 166,500 | $ 166,600 |  |
Concentration risk percentage |  |  | 24.50% | 16.90% |  |
Customer Concentration Risk | Trade Accounts Receivable and Costs and Estimated Earnings | AT&T Inc. |  |  |  |  |  |
Concentration Risk |  |  |  |  |  |
Accounts receivable, net | 338,700 |  | $ 98,200 | $ 338,700 |  |
Concentration risk percentage |  |  | 14.40% | 34.30% |  |
Customer Concentration Risk | Trade Accounts Receivable and Costs and Estimated Earnings | CenturyLink, Inc. |  |  |  |  |  |
Concentration Risk |  |  |  |  |  |
Accounts receivable, net | 142,800 |  | $ 126,000 | $ 142,800 |  |
Concentration risk percentage |  |  | 18.50% | 14.50% |  |
Customer Concentration Risk | Trade Accounts Receivable and Costs and Estimated Earnings | AT&T Inc. |  |  |  |  |  |
Concentration Risk |  |  |  |  |  |
Accounts receivable, net | $ 102,700 |  | $ 79,200 | $ 102,700 |  |
Concentration risk percentage |  |  | 11.60% | 10.40% |  |

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