XML 67 R52.htm IDEA: XBRL DOCUMENT v3.20.4

Lease Obligations - Additional information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Operating And Finance Leases [Line Items]
Option to extend lease term (up to)	5 years
Option to terminate leases, period	1 year
Minimum lease payments required	$ 26,803
Employees | Subsidiaries
Operating And Finance Leases [Line Items]
Minimum lease payments required	$ 3,300
Lease amortization period	3 years 6 months
Minimum
Operating And Finance Leases [Line Items]
Remaining lease term	1 year
Maximum
Operating And Finance Leases [Line Items]
Remaining lease term	6 years

X

- Definition

Lessee, operating and finance leases, option to extend, term.

+ References

No definition available.

+ Details

Name:	myrg_LesseeOperatingAndFinanceLeasesOptionToExtendTerm
Namespace Prefix:	myrg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Lessee, operating and finance leases, option to terminate, period.

+ References

No definition available.

+ Details

Name:	myrg_LesseeOperatingAndFinanceLeasesOptionToTerminatePeriod
Namespace Prefix:	myrg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Lessee operating and finance leases remaining contract term.

+ References

No definition available.

+ Details

Name:	myrg_LesseeOperatingAndFinanceLeasesRemainingContractTerm
Namespace Prefix:	myrg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

It represents Lessee Operating Lease Amortization Period.

+ References

No definition available.

+ Details

Name:	myrg_LesseeOperatingLeaseAmortizationPeriod
Namespace Prefix:	myrg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

n/a

+ References

No definition available.

+ Details

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

X

- Definition

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

+ References

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=121609121&loc=SL77918701-209980

+ Details

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

X

- Details

Name:	srt_TitleOfIndividualAxis=myrg_EmployeesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=srt_SubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: