Name:	myrg_FinanceLeaseLiabilityPaymentsDueAfterYearSix
Namespace Prefix:	myrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for finance lease, due in sixth fiscal year following latest fiscal year.

No definition available.

Name:	myrg_FinanceLeaseLiabilityPaymentsDueYearSix
Namespace Prefix:	myrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of total lease liability.

No definition available.

Name:	myrg_LeaseLiability
Namespace Prefix:	myrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lease liability classified as current.

No definition available.

Name:	myrg_LeaseLiabilityCurrent
Namespace Prefix:	myrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lease liability classified as noncurrent.

No definition available.

Name:	myrg_LeaseLiabilityNoncurrent
Namespace Prefix:	myrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments.

No definition available.

Name:	myrg_LeaseLiabilityPaymentsDue
Namespace Prefix:	myrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for lease, due after sixth fiscal year following latest fiscal year.

No definition available.

Name:	myrg_LeaseLiabilityPaymentsDueAfterYearSix
Namespace Prefix:	myrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for lease, due in fifth fiscal year following latest fiscal year.

No definition available.

Name:	myrg_LeaseLiabilityPaymentsDueYearFive
Namespace Prefix:	myrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for lease, due in fourth fiscal year following latest fiscal year.

No definition available.

Name:	myrg_LeaseLiabilityPaymentsDueYearFour
Namespace Prefix:	myrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for lease, due in sixth fiscal year following latest fiscal year.

No definition available.

Name:	myrg_LeaseLiabilityPaymentsDueYearSix
Namespace Prefix:	myrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for lease, due in third fiscal year following latest fiscal year.

No definition available.

Name:	myrg_LeaseLiabilityPaymentsDueYearThree
Namespace Prefix:	myrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for lease, due in second fiscal year following latest fiscal year.

No definition available.

Name:	myrg_LeaseLiabilityPaymentsDueYearTwo
Namespace Prefix:	myrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for lease having an initial or remaining lease term in excess of one year due in remainder of fiscal year following latest fiscal year.

No definition available.

Name:	myrg_LeaseLiabilityPaymentsRemainderOfFiscalYear
Namespace Prefix:	myrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments.

No definition available.

Name:	myrg_LeaseLiabilityUndiscountedExcessAmount
Namespace Prefix:	myrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for operating lease, due after sixth fiscal year following latest fiscal year.

No definition available.

Name:	myrg_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearSix
Namespace Prefix:	myrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for operating lease, due in sixth fiscal year following latest fiscal year.

No definition available.

Name:	myrg_LesseeOperatingLeaseLiabilityPaymentsDueYearSix
Namespace Prefix:	myrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

Name:	myrg_TotalLeaseObligationsAbstract
Namespace Prefix:	myrg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

Name:	us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Present value of lessee's discounted obligation for lease payments from finance lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918701-209980

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977

Name:	us-gaap_FinanceLeaseLiability
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Present value of lessee's discounted obligation for lease payments from finance lease, classified as current.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977

Name:	us-gaap_FinanceLeaseLiabilityCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Present value of lessee's discounted obligation for lease payments from finance lease, classified as noncurrent.

Name:	us-gaap_FinanceLeaseLiabilityNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for finance lease.

Name:	us-gaap_FinanceLeaseLiabilityPaymentsDue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for finance lease, due in fifth fiscal year following latest fiscal year.

Name:	us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for finance lease, due in fourth fiscal year following latest fiscal year.

Name:	us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for finance lease, due in third fiscal year following latest fiscal year.

Name:	us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for finance lease, due in second fiscal year following latest fiscal year.

Name:	us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for finance lease, due in remainder of fiscal year following latest fiscal year ended.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918701-209980

Name:	us-gaap_FinanceLeaseLiabilityPaymentsRemainderOfFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for finance lease.

Name:	us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for operating lease.

Name:	us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for operating lease, due in fifth fiscal year following latest fiscal year.

Name:	us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for operating lease, due in fourth fiscal year following latest fiscal year.

Name:	us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for operating lease, due in third fiscal year following latest fiscal year.

Name:	us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for operating lease, due in second fiscal year following latest fiscal year.

Name:	us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments for operating lease having an initial or remaining lease term in excess of one year due in remainder of fiscal year following latest fiscal year.

Name:	us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating lease.

Name:	us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

Name:	us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Present value of lessee's discounted obligation for lease payments from operating lease.

Name:	us-gaap_OperatingLeaseLiability
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Present value of lessee's discounted obligation for lease payments from operating lease, classified as current.

Name:	us-gaap_OperatingLeaseLiabilityCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent.