Commitments and Contingencies (Details) - USD ($) $ in Thousands	Apr. 17, 2020	Jan. 23, 2020	Nov. 13, 2019	Oct. 12, 2018	Jun. 30, 2020	Dec. 31, 2019	Dec. 31, 2018
Loss Contingencies [Line Items]
Litigation settlement, amount awarded to other party				$ 30,000
Other current assets liabilities							$ 30,000
Long-term debt					$ 41,000	$ 41,000
Surety Bond
Loss Contingencies [Line Items]
Long-term debt					$ 128,600
Bernards Bros vs. Limbach Holdings | Pending Litigation
Loss Contingencies [Line Items]
Loss contingency, damages sought, value		$ 3,000
Lanzo Trenchless Technologies vs. Limbach Company LLC | Pending Litigation
Loss Contingencies [Line Items]
Loss contingency, damages sought, value			$ 400
LA Excavating, Inc. vs. Limbach Company LP [Member] | Pending Litigation
Loss Contingencies [Line Items]
Loss contingency, damages sought, value	$ 1,000