Leases - Income Generated as Lessor (Details) $ in Millions	9 Months Ended
Sep. 30, 2019 USD ($)
Leases [Abstract]
Lessor, Operating Lease, Payments to be Received	$ 0.2
Lessor, Operating Lease, Assumptions and Judgments, Value of Underlying Asset, Amount	0.4
Lessor, Operating lease, payments to be received from Decatur lease	$ 0.1

Lessor, Operating lease, payments to be received from Decatur lease

No definition available.

Name:	laws_LessorOperatingleasepaymentstobereceivedfromDecaturlease
Namespace Prefix:	laws_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

Amount lessor expects from underlying asset following end of operating lease term.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=77888428&loc=SL77919359-209981

+ Details

Name:	us-gaap_LessorOperatingLeaseAssumptionsAndJudgmentsValueOfUnderlyingAssetAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of lease payments to be received by lessor for operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=77888428&loc=SL77919396-209981

+ Details

Name:	us-gaap_LessorOperatingLeasePaymentsToBeReceived
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant