Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3367-108585

+ Details

Name:	us-gaap_PaymentsForRestructuring
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 5.P.3)
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140864-122747

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

+ Details

Name:	us-gaap_RestructuringCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

+ Details

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

- Definition

Amount of increase (decrease) in the accrual for restructuring costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

+ Details

Name:	us-gaap_RestructuringReservePeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=us-gaap_AccountingStandardsUpdate201602Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=us-gaap_EmployeeSeveranceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=lqdt_OccupancyAndOtherCostsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidationItemsAxis=us-gaap_CorporateNonSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=lqdt_CAGMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Business Realignment Expenses - Restructuring Related Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019	Sep. 30, 2019
Restructuring Reserve [Roll Forward]
Beginning balance			$ 821	$ 1,376	$ 1,376
Restructuring Charges	$ 0	$ 5	0	355	2,165
Cash Payments			(652)		(2,720)
Ending balance	0		0		821
ASU 2016-02
Restructuring Reserve [Roll Forward]
Adoption of ASC 842			(169)
Employee severance and benefit costs
Restructuring Reserve [Roll Forward]
Beginning balance			652	110	110
Restructuring Charges	0	0	0	170	1,980
Cash Payments			(652)		(1,438)
Ending balance	0		0		652
Employee severance and benefit costs \| ASU 2016-02
Restructuring Reserve [Roll Forward]
Adoption of ASC 842			0
Occupancy and other costs
Restructuring Reserve [Roll Forward]
Beginning balance			169	1,266	1,266
Restructuring Charges	0	5	0	185	185
Cash Payments			0		(1,282)
Ending balance	0		0		169
Occupancy and other costs \| ASU 2016-02
Restructuring Reserve [Roll Forward]
Adoption of ASC 842			(169)
Corporate & Other \| Employee severance and benefit costs
Restructuring Reserve [Roll Forward]
Beginning balance			238	21	21
Restructuring Charges	0	0	0	170	1,537
Cash Payments			(238)		(1,320)
Ending balance	0		0		238
Corporate & Other \| Employee severance and benefit costs \| ASU 2016-02
Restructuring Reserve [Roll Forward]
Adoption of ASC 842			0
Corporate & Other \| Occupancy and other costs
Restructuring Reserve [Roll Forward]
Beginning balance			0	807	807
Restructuring Charges	0	0	0	134	134
Cash Payments			0		(941)
Ending balance	0		0		0
Corporate & Other \| Occupancy and other costs \| ASU 2016-02
Restructuring Reserve [Roll Forward]
Adoption of ASC 842			0
CAG \| Employee severance and benefit costs
Restructuring Reserve [Roll Forward]
Beginning balance			414	89	89
Restructuring Charges	0	0	0	0	443
Cash Payments			(414)		(118)
Ending balance	0		0		414
CAG \| Employee severance and benefit costs \| ASU 2016-02
Restructuring Reserve [Roll Forward]
Adoption of ASC 842			0
CAG \| Occupancy and other costs
Restructuring Reserve [Roll Forward]
Beginning balance			169	459	459
Restructuring Charges	0	$ 5	0	$ 51	51
Cash Payments			0		(341)
Ending balance	$ 0		0		$ 169
CAG \| Occupancy and other costs \| ASU 2016-02
Restructuring Reserve [Roll Forward]
Adoption of ASC 842			$ (169)