XML 67 R55.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Accounts Receivable Concentration Risk (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jul. 28, 2018 | Jul. 29, 2017 | Jul. 28, 2018 | Jan. 27, 2018 | Jul. 29, 2017 | Jan. 28, 2018
Concentration Risk |  |  |  |  |  |
Accounts receivable, net | $ 684,862 |  | $ 684,862 | $ 318,684 |  | $ 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 | $ 160,800 |  | $ 160,800 | $ 166,500 |  |
Concentration risk percentage |  |  | 19.00% | 24.50% |  |
Customer Concentration Risk | Trade Accounts Receivable and Costs and Estimated Earnings | Verizon Communications Inc. |  |  |  |  |  |
Concentration Risk |  |  |  |  |  |
Accounts receivable, net | 241,300 |  | $ 241,300 | $ 98,200 |  |
Concentration risk percentage |  |  | 28.50% | 14.40% |  |
Customer Concentration Risk | Trade Accounts Receivable and Costs and Estimated Earnings | CenturyLink, Inc. |  |  |  |  |  |
Concentration Risk |  |  |  |  |  |
Accounts receivable, net | 126,500 |  | $ 126,500 | $ 126,000 |  |
Concentration risk percentage |  |  | 15.00% | 18.50% |  |
Customer Concentration Risk | Trade Accounts Receivable and Costs and Estimated Earnings | AT&T Inc. |  |  |  |  |  |
Concentration Risk |  |  |  |  |  |
Accounts receivable, net | $ 98,100 |  | $ 98,100 | $ 79,200 |  |
Concentration risk percentage |  |  | 11.60% | 11.60% |  |

X
- Definition Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 8 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130549-203045 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(3)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_AccountsReceivableNetCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ConcentrationRiskLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13531-108611 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13537-108611 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592 + Details
Name: | us-gaap_ConcentrationRiskPercentage1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CustomerConcentrationRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByBenchmarkAxis=dy_TradeAccountsReceivableandCostsandEstimatedEarningsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=dy_ComcastMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=dy_VerizonMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=dy_CenturylinkMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=dy_AttMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |