XML 62 R50.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Acquisitions - Narratives (Details) - USD ($) $ in Millions | 1 Months Ended | 6 Months Ended
--- | --- | ---
Mar. 31, 2018 | Mar. 31, 2017 | Jul. 28, 2018
Business Acquisition [Line Items] |  |  |
Working capital adjustment |  |  | $ 0.5
Aero Communications, Inc. |  |  |
Business Acquisition [Line Items] |  |  |
Payment to acquire business, net of cash acquired | $ 20.9 |  |
Texstar Enterprises, Inc. |  |  |
Business Acquisition [Line Items] |  |  |
Payment to acquire business, net of cash acquired |  | $ 26.1 |

X
- Definition Business Combination, Purchase Accounting Adjustment to Receivables + References No definition available. + Details
Name: | dy_BusinessCombinationPurchaseAccountingAdjustmenttoReceivables
Namespace Prefix: | dy_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585 + Details
Name: | us-gaap_PaymentsToAcquireBusinessesGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=dy_AeroCommunicationsInc.Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=dy_TexstarEnterprisesInc.Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |