Contracts in Process (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Contracts in Process [Line Items]
Costs and estimated earnings on uncompleted contracts	$ 1,809,454	$ 1,746,507
Less: Billings to date	1,777,803myrg_BillingsToDate	1,740,019myrg_BillingsToDate
Net Costs And Estimated Earnings In Excess Of Billings	$ 31,651	$ 6,488

Represents the net costs and estimated earnings in excess of billings on uncompleted contracts accounted for under the percentage-of-completion method.

No definition available.

Name:	myrg_NetCostsAndEstimatedEarningsInExcessOfBillings
Namespace Prefix:	myrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant