INVENTORY, NET (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Current
Raw materials and consumables	$ 1,082	$ 941
Fuel products	583	688
Work in progress	775	674
RTFO certificates	372	342
Finished goods and other	907	845
Carrying amount of inventories	3,719	3,490
RTFO certificates held for trading and recorded at fair value	$ 25	$ 66

Renewable Transport Fuel Obligation Certificates

No definition available.

Name:	bbu_RenewableTransportFuelObligationCertificates
Namespace Prefix:	bbu_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Renewable Transport Fuel Obligation Certificates Held For Trading

+ References

No definition available.

+ Details

Name:	bbu_RenewableTransportFuelObligationCertificatesHeldForTrading
Namespace Prefix:	bbu_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	ifrs-full_ClassesOfInventoriesAbstract
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

A classification of current inventory representing the amount of fuel. [Refer: Inventories]

+ References

+ Details

Name:	ifrs-full_CurrentFuel
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

A classification of current inventory representing the amount of current raw materials and current production supplies. [Refer: Current production supplies; Current raw materials]

+ References

+ Details

Name:	ifrs-full_CurrentRawMaterialsAndCurrentProductionSupplies
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

A classification of current inventory representing the amount of goods that have completed the production process and are held for sale in the ordinary course of business. [Refer: Inventories]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 2
-IssueDate 2019-01-01
-Paragraph 37
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=2&code=ifrs-tx-2019-en-r&anchor=para_37&doctype=Standard
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 78
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_78_c&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_FinishedGoods
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of current inventories. [Refer: Inventories]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 2
-IssueDate 2019-01-01
-Paragraph 36
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=2&code=ifrs-tx-2019-en-r&anchor=para_36_b&doctype=Standard
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 54
-Subparagraph g
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_54_g&doctype=Standard
-URIDate 2019-03-27

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 68
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_68&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_Inventories
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

A classification of current inventory representing the amount of assets currently in production, which require further processes to be converted into finished goods or services. [Refer: Current finished goods; Inventories]

+ References

+ Details

Name:	ifrs-full_WorkInProgress
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant