Amount of financial advisory fees of the business combination , incurred to consummate the business acquisition.

No definition available.

Name:	rba_BusinessAcquisitionFinancialAdviserFees
Namespace Prefix:	rba_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of refund of direct costs of the business combination including legal, accounting, and other costs incurred to consummate the business acquisition.

+ References

No definition available.

+ Details

Name:	rba_BusinessAcquisitionRefundOfTransactionCosts
Namespace Prefix:	rba_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of direct costs of the business combination including legal, accounting, and other costs, net of refund, incurred to consummate the business acquisition.

+ References

No definition available.

+ Details

Name:	rba_BusinessAcquisitionTransactionCostsNetOfRefund
Namespace Prefix:	rba_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Period over which grantee's right to exercise award under business combination arrangement over the service period, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

No definition available.

+ Details

Name:	rba_BusinessCombinationConsiderationEquityIssuedVestingPeriod
Namespace Prefix:	rba_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of equity shares of the acquirer, including instruments or interests issued or issuable in consideration for the business combination.

+ References

No definition available.

+ Details

Name:	rba_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuableShares
Namespace Prefix:	rba_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred, including working capital adjustments by the acquirer, and equity interest issued by the acquirer.

+ References

No definition available.

+ Details

Name:	rba_BusinessCombinationConsiderationTransferredIncludingWorkingCapitalAdjustments
Namespace Prefix:	rba_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Adjustments to decrease liabilities assumed.

+ References

No definition available.

+ Details

Name:	rba_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesDecreaseAdjustment
Namespace Prefix:	rba_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Adjustments to increase liabilities assumed.

+ References

No definition available.

+ Details

Name:	rba_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesIncreaseAdjustment
Namespace Prefix:	rba_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Reduction in purchase price due to working capital adjustment under purchase agreement.

+ References

No definition available.

+ Details

Name:	rba_BusinessCombinationReductionInPurchasePrice
Namespace Prefix:	rba_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

For transactions that are recognized separately from the acquisition of assets and assumptions of liabilities in the business combination, such as related to pre-existing relationships with the acquiree, this element represents the disclosure of the amount of acquisition related share based continuing employment costs which have been expensed.

+ References

No definition available.

+ Details

Name:	rba_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresShareBasedContinuingEmploymentCosts
Namespace Prefix:	rba_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Business Combinations, Cash Consideration, Transferred to Escrow

+ References

No definition available.

+ Details

Name:	rba_BusinessCombinationsCashConsiderationTransferredToEscrow
Namespace Prefix:	rba_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount received from escrow on closure of acquisition.

+ References

No definition available.

+ Details

Name:	rba_BusinessCombinationsPostClosingReleaseFromEscrow
Namespace Prefix:	rba_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Reduction in borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

No definition available.

+ Details

Name:	rba_LineOfCreditFacilityReductionInBorrowingCapacity
Namespace Prefix:	rba_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The cash outflow associated with the acquisition of business during the period, including cash placed in escrow.

+ References

No definition available.

+ Details

Name:	rba_PaymentsToAcquireBusinessesIncludingEscrow
Namespace Prefix:	rba_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of expected to vest shares-based payment award that may be converted into shares.

+ References

No definition available.

+ Details

Name:	rba_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpectedToVestNumber
Namespace Prefix:	rba_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=116868678&loc=d3e1043-128460

+ Details

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

- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6613-128477

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6578-128477

+ Details

Name:	us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of equity interests of the acquirer, including instruments or interests issued or issuable in consideration for the business combination.

+ References

+ Details

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

- Definition

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

+ Details

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

- Definition

Amount of noncash expense (reversal of expense) for employee benefits and share-based payment arrangement. Includes, but is not limited to, pension, other postretirement, postemployment and termination benefits.

+ References

Reference 1: 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=121586364&loc=d3e3602-108585

+ Details

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

- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

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

- Definition

The designation of funds furnished by a borrower to a lender to assure future payments of the borrower's real estate taxes and insurance obligations with respect to a mortgaged property. Escrow deposits may be made for a variety of other purposes such as earnest money and contingent payments. This element excludes replacement reserves which are an escrow separately provided for within the US GAAP taxonomy.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10)
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

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

- Definition

Amount of increase (decrease) of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3213-108585

+ Details

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

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_BusinessAcquisitionAxis=rba_RouseServicesLlcMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=rba_EmploymentCostsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=rba_EuroAuctionsLimitedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=rba_GoldmanSachsBankUsaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=rba_SmartequipMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=rba_TermLoanFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_BridgeLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Business Combinations (Narrative) (Details)					3 Months Ended			9 Months Ended	12 Months Ended
Business Combinations (Narrative) (Details)	Nov. 02, 2021 shares	Aug. 09, 2021 USD ($)	Aug. 09, 2021 GBP (£)	Dec. 08, 2020 USD ($) shares	Sep. 30, 2021 USD ($) shares	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($) shares	Sep. 30, 2021 USD ($) shares	Dec. 31, 2022 USD ($)	Sep. 21, 2021 USD ($)	Aug. 08, 2021 USD ($)	Sep. 30, 2020 USD ($)
Rouse Services LLC [Member]
Business Acquisition [Line Items]
Total purchase price				$ 251,724,000
Cash consideration paid, including cash placed in escrow				250,265,000
Total consideration				250,996,000
Cash consideration				249,537,000		$ 249,537,000
Cash consideration, placed in escrow				$ 2,169,000
Post-closing release from escrow						728,000
Increase in liabilities assumed							$ 603,000
Reduction in purchase price						728,000
Decrease in liabilities assumed						1,677,000
Decrease in goodwill						$ 1,802,000
Escrow deposit					$ 1,169,000			$ 1,169,000
Common stock consideration (in shares) \| shares				312,193
Vesting period				3 years
Common stock consideration fair value				$ 1,459,000
Shares forfeited \| shares							55,510	55,510
Reversal of share based continuing employment costs							$ 98,000
Number of common shares expected to vest \| shares					256,683			256,683
Unrecognized share based continuing employment costs					$ 9,191,000			$ 9,191,000				$ 0
Acquisition-related costs for legal, advisory, integration and other professional fees					3,021,000
Acquisition related share based continuing employment costs					2,707,000
Rouse Services LLC [Member] \| Employment Costs [Member]
Business Acquisition [Line Items]
Common stock consideration fair value				$ 20,735,000
Euro Auctions Limited [Member]
Business Acquisition [Line Items]
Cash consideration		$ 1,040,000,000.00	£ 775,000,000
Acquisition-related costs					6,133,000
Euro Auctions Limited [Member] \| GS Bank [Member]
Business Acquisition [Line Items]
Financial adviser fees											$ 15,000,000
Refund of financial adviser fees											2,000,000
Financial adviser fees, net of refund											13,000,000
SmartEquip [Member]
Business Acquisition [Line Items]
Acquisition-related costs					$ 1,101,000
Subsequent Events [Member] \| SmartEquip [Member]
Business Acquisition [Line Items]
Total consideration									$ 175,000,000
Common stock consideration (in shares) \| shares	63,971
Revolving Credit Facility [Member] \| Euro Auctions Limited [Member] \| GS Bank [Member]
Business Acquisition [Line Items]
Maximum borrowing capacity											530,000,000
Term Loan Facility [Member] \| Euro Auctions Limited [Member] \| GS Bank [Member]
Business Acquisition [Line Items]
Maximum borrowing capacity											100,000,000
Bridge Commitments [Member] \| Euro Auctions Limited [Member] \| GS Bank [Member]
Business Acquisition [Line Items]
Maximum borrowing capacity										$ 950,000,000	$ 1,150,000,000
Reduction in borrowing capacity										$ 200,000,000