Contract Assets and Liabilities - Schedule of Contracts In Progress (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue earned on uncompleted contracts	$ 743,559	$ 726,215
Less: Billings to date	(752,603)	(722,562)
Net (overbilling) underbilling	(9,044)	3,653
Costs in excess of billings and estimated earnings	38,407	44,315
Billings in excess of costs and estimated earnings	$ (47,451)	$ (40,662)

The amount of billings that were raised on the contracts to date during the period.

No definition available.

Name:	lmb_BillingsToDateOnContracts
Namespace Prefix:	lmb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Billings in Excess of Billings and Estimated Earnings on Uncompleted Contracts

No definition available.

Name:	lmb_BillingsinExcessofBillingsandEstimatedEarningsonUncompletedContracts
Namespace Prefix:	lmb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Costs in Excess of Billings and Estimated Earnings on Uncompleted Contracts

No definition available.

Name:	lmb_CostsinExcessofBillingsandEstimatedEarningsonUncompletedContracts
Namespace Prefix:	lmb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The amount of Asset or liability for net Under Over billings on the contracts.

No definition available.

Name:	lmb_NetUnderOverbillingOnContracts
Namespace Prefix:	lmb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of revenue earned from uncompleted contracts during the period.

No definition available.

Name:	lmb_RevenueEarnedOnUncompletedContracts
Namespace Prefix:	lmb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

No definition available.

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