Contingencies (Details) - USD ($)	3 Months Ended	12 Months Ended
Mar. 31, 2020	Dec. 31, 2019
Contingencies
Assets guaranteed under contract	$ 110,703,000	$ 63,612,000
Percentage of assets expected to be sold	89.00%	39.00%

Minimum level of proceeds guaranteed to consignors on the sale at auction of that consignor's equipment.

No definition available.

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