The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

No definition available.

Name:	rba_MajorityInterestOwnershipPercentageByParent
Namespace Prefix:	rba_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Period in which the company has an obligation to pay additional amounts, starting from the acquisition date

+ References

No definition available.

+ Details

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

- Definition

Total consideration for acquisition of contingently redeemable non-controlling interests.

+ References

No definition available.

+ Details

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

- Definition

Fair value of consideration for acquisition of contingently redeemable non-controlling interests that is contingent upon achievement of certain conditions.

+ References

No definition available.

+ Details

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

- Definition

Fair value of the consideration payable to former contingently redeemable non-controlling interest holders that is contingent upon those former non-controlling interest holders providing continued management services to the Company.

+ References

No definition available.

+ Details

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

- Definition

Maximum amount of consideration for acquisition of contingently redeemable non-controlling interests that is contingent upon achievement of certain conditions.Maximum Value of Consideration

+ References

No definition available.

+ Details

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

- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

+ References

No definition available.

+ Details

Name:	us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash outflow during the period for redemption of redeemable noncontrolling interests.

+ References

No definition available.

+ Details

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

- Definition

As of the reporting date, the carrying amount of noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. The noncontrolling interest holder's ownership (or holders' ownership) may be in the form of common shares (regardless of class), limited partnership units (regardless of class), non-preferential membership interests, or any other form of common equity regardless of investee entity legal form.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 3A
-Subparagraph (16)(c)
-URI http://asc.fasb.org/extlink&oid=27011957&loc=SL6540498-122764

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 3A
-Subparagraph (12)(c)
-URI http://asc.fasb.org/extlink&oid=27011957&loc=SL6540498-122764

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 3A
-Subparagraph 15
-URI http://asc.fasb.org/extlink&oid=27011957&loc=SL6540498-122764

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 3A
-Subparagraph 14
-URI http://asc.fasb.org/extlink&oid=27011957&loc=SL6540498-122764

+ Details

Name:	us-gaap_RedeemableNoncontrollingInterestEquityCommonCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_RedeemableNoncontrollingInterestLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	dei_LegalEntityAxis=rba_RitchieBrosFinancialServicesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Contingently Redeemable Non-controlling Interest in Ritchie Bros. Financial Services (Details) CAD in Thousands, $ in Thousands			9 Months Ended
	Jul. 12, 2016 CAD	Jul. 12, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jul. 12, 2016 USD ($)	Dec. 31, 2015 USD ($)
Redeemable Noncontrolling Interest [Line Items]
Redemption value of the contingently redeemable NCI \| $					$ 24,785
Cash consideration \| $			$ 41,092
Ritchie Bros. Financial Services [Member]
Redeemable Noncontrolling Interest [Line Items]
Percentage of ownership interest			51.00%
Percentage ownership by non-controlling interest holders	49.00%		49.00%	49.00%
Total consideration	CAD 57,900	$ 44,141
Cash consideration	53,900	$ 41,092
Contingent consideration	4,000			$ 3,049
Additional cash compensation for continuted management services \| CAD	CAD 1,500
Period to make additional amount of obligation upon achievement of certain condition	3 years	3 years
Maximum [Member] \| Ritchie Bros. Financial Services [Member]
Redeemable Noncontrolling Interest [Line Items]
Additional cash compensation \| CAD	CAD 10,000