Contract Assets and Liabilities - Contracts in process (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Abstract]
Costs and estimated earnings on uncompleted contracts	$ 11,716,976	$ 8,368,365
Less: billings to date	11,870,261	8,593,893
Net asset position for contracts in process	$ (153,285)	$ (225,528)

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