XML 86 R68.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Employee Benefit Plans (Details Textual) $ in Millions | 12 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Dec. 31, 2015 USD ($) | Dec. 31, 2014 USD ($) | Dec. 31, 2013 USD ($) | Mar. 31, 2015 | Jun. 30, 2014 | Mar. 31, 2014 | Jun. 30, 2013 | Mar. 31, 2013
Eighth District Electrical Pension Fund [Member] |  |  |  |  |  |  |  |
Defined Contribution Plans [Line Items] |  |  |  |  |  |  |  |
Multiemployer Plans, Collective-Bargaining Arrangement, Percentage of Employer's Contributions |  |  |  | 5.00% |  | 5.00% |  | 5.00%
IBEW Local 1249 Pension Plan [Member] |  |  |  |  |  |  |  |
Defined Contribution Plans [Line Items] |  |  |  |  |  |  |  |
Multiemployer Plans, Collective-Bargaining Arrangement, Percentage of Employer's Contributions |  | 5.00% | 5.00% |  |  |  |  |
IBEW Local 769 Management Pension Plan [Member] |  |  |  |  |  |  |  |
Defined Contribution Plans [Line Items] |  |  |  |  |  |  |  |
Multiemployer Plans, Collective-Bargaining Arrangement, Percentage of Employer's Contributions |  |  |  |  | 5.00% |  | 5.00% |
Multiemployer Plans, Pension [Member] |  |  |  |  |  |  |  |
Defined Contribution Plans [Line Items] |  |  |  |  |  |  |  |
Number Of Locals Covered Under Multiemployer Defined Plans | 100 |  |  |  |  |  |  |
Multiemployer Plans, Pension [Member] | Maximum [Member] |  |  |  |  |  |  |  |
Defined Contribution Plans [Line Items] |  |  |  |  |  |  |  |
Multiemployer Plans Red Zone Funded Status Percentage | 65.00% |  |  |  |  |  |  |
Multiemployer Plans Yellow Zone Funded Status Percentage | 80.00% |  |  |  |  |  |  |
Multiemployer Plans, Pension [Member] | Minimum [Member] |  |  |  |  |  |  |  |
Defined Contribution Plans [Line Items] |  |  |  |  |  |  |  |
Multiemployer Plans Green Zone Funded Status Percentage | 80.00% |  |  |  |  |  |  |
Employee Benefit Plan [Member] |  |  |  |  |  |  |  |
Defined Contribution Plans [Line Items] |  |  |  |  |  |  |  |
Defined Contribution Plan, Cost Recognized | $ 0.7 | $ 0.6 | $ 0.6 |  |  |  |  |
Profit Sharing and Thrift Employee Benefit Plan [Member] |  |  |  |  |  |  |  |
Defined Contribution Plans [Line Items] |  |  |  |  |  |  |  |
Defined Contribution Plan, Cost Recognized | $ 3.4 | $ 6.9 | $ 4.9 |  |  |  |  |

X
- References No definition available. + Details
Name: | myrg_DefinedContributionPlansLineItems
Namespace Prefix: | myrg_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the percentage funded for green zone status. + References No definition available. + Details
Name: | myrg_MultiemployerPlansGreenZoneFundedStatusPercentage
Namespace Prefix: | myrg_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the percentage funded for red zone status. + References No definition available. + Details
Name: | myrg_MultiemployerPlansRedZoneFundedStatusPercentage
Namespace Prefix: | myrg_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the percentage funded for yellow zone status. + References No definition available. + Details
Name: | myrg_MultiemployerPlansYellowZoneFundedStatusPercentage
Namespace Prefix: | myrg_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents information pertaining to number of locals covered under multiemployer defined plan. + References No definition available. + Details
Name: | myrg_NumberOfLocalsCoveredUnderMultiemployerDefinedPlans
Namespace Prefix: | myrg_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition The amount of the cost recognized during the period for defined contribution plans. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 70 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942 + Details
Name: | us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of contributions required by a collective bargaining arrangement to all contributions required of an employer related to a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 80 -Section 50 -Paragraph 5 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=49170332&loc=SL14450657-114947 + Details
Name: | us-gaap_MultiemployerPlansCollectiveBargainingArrangementPercentageOfEmployersContributions
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_MultiemployerPlanNameAxis=myrg_EighthDistrictElectricalPensionFundMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MultiemployerPlanNameAxis=myrg_IbewLocal1249PensionPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MultiemployerPlanNameAxis=myrg_IbewLocal769ManagementPensionPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MultiemployerPlanTypeAxis=us-gaap_MultiemployerPlansPensionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | myrg_DefinedContributionPlansAxis=myrg_EmployeeBenefitPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | myrg_DefinedContributionPlansAxis=myrg_ProfitSharingAndThriftEmployeeBenefitPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |