Contract Assets and Liabilities - Contracts in process (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Costs and estimated earnings on uncompleted contracts	$ 2,448,984	$ 2,718,713
Less: Billings to date	2,346,199	2,664,611
Net asset position for contracts in process	$ 102,785	$ 54,102

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