Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Commitments and Contingencies (Details) - USD ($) $ in Millions				1 Months Ended
	Apr. 17, 2020	Jan. 23, 2020	Nov. 13, 2019	Jul. 31, 2020	Dec. 31, 2020
Surety Bond
Loss Contingencies [Line Items]
Long-term debt					$ 79.4
Lanzo Trenchless Technologies vs. Limbach Company LLC \| Pending Litigation
Loss Contingencies [Line Items]
Loss contingency, damages sought, value			$ 0.4
Bernards Bros vs. Limbach Holdings \| Pending Litigation
Loss Contingencies [Line Items]
Loss contingency, damages sought, value		$ 3.0
LA Excavating, Inc. vs. Limbach Company LP \| Pending Litigation
Loss Contingencies [Line Items]
Loss contingency, damages sought, value	$ 1.0
Kimball Construction Co., Inc. vs. Limbach Company LLC \| Pending Litigation
Loss Contingencies [Line Items]
Loss contingency, damages sought, value				$ 1.7