ACQUISITION OF BUSINESSES - DexKo Global Inc. (“DexKo”) (Details) - DexKo Global Inc. - Industrials - USD ($) $ in Millions		12 Months Ended
Oct. 04, 2021	Dec. 31, 2021
Disclosure of detailed information about business combination [line items]
Percentage of voting equity interests acquired	35.00%
Equity from the partnership	$ 396
Voting interest	100.00%
Goodwill	$ 1,400
Intangible assets	2,200
Acquisition-related costs	$ 9
Revenue of acquiree since acquisition date		$ 587
Profit (loss) of acquiree since acquisition date		22
Revenue of combined entity as if combination occurred at beginning of period		2,500
Profit (loss) of combined entity as if combination occurred at beginning of period		$ 49
Brookfield Business Partners L.P. and Institutional Investors
Disclosure of detailed information about business combination [line items]
Percentage of voting equity interests acquired	100.00%
Consideration transferred, acquisition-date fair value	$ 3,800
Equity from the partnership	1,100
Debt raised incurred	2,600
Contingent consideration	30
Non-controlling interest in acquiree recognised at acquisition date	$ 761

Debt Raised Incurred

No definition available.

Name:	bbu_DebtRaisedIncurred
Namespace Prefix:	bbu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fair value, at acquisition date, of the consideration transferred in a business combination. [Refer: Business combinations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph B64
-Subparagraph f
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64_f&doctype=Appendix&subtype=B
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_AcquisitiondateFairValueOfTotalConsiderationTransferred
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of acquisition-related costs recognised as an expense for transactions that are recognised separately from the acquisition of assets and the assumption of liabilities in business combinations. [Refer: Business combinations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph B64
-Subparagraph m
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64_m&doctype=Appendix&subtype=B
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_AcquisitionrelatedCostsRecognisedAsExpenseForTransactionRecognisedSeparatelyFromAcquisitionOfAssetsAndAssumptionOfLiabilitiesInBusinessCombination
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount, at acquisition date, of contingent consideration arrangements recognised as consideration transferred in a business combination. [Refer: Business combinations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph B64
-Subparagraph g
-Clause i
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64_g_i&doctype=Appendix&subtype=B
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_ContingentConsiderationRecognisedAsOfAcquisitionDate
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

The fair value, at the acquisition date, of equity interests of the acquirer transferred as consideration in a business combination. [Refer: Business combinations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph B64
-Subparagraph f
-Clause iv
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64_f_iv&doctype=Appendix&subtype=B
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_EquityInterestsOfAcquirer
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount recognised as of the business combination's acquisition date for goodwill. [Refer: Goodwill; Business combinations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph B64
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64&doctype=Appendix&subtype=B
-URIDate 2021-03-24

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph IE72
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_IE72&doctype=Illustrative%20Examples
-URIDate 2021-03-24

+ Details

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

- Definition

The amount recognised as of the acquisition date for identifiable intangible assets acquired in a business combination. [Refer: Intangible assets other than goodwill; Business combinations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph B64
-Subparagraph i
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64_i&doctype=Appendix&subtype=B
-URIDate 2021-03-24

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph IE72
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_IE72&doctype=Illustrative%20Examples
-URIDate 2021-03-24

+ Details

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

- Definition

The amount of non-controlling interest in the acquiree recognised at the acquisition date for business combinations in which the acquirer holds less than 100 per cent of the equity interests in the acquiree at the acquisition date. [Refer: Business combinations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph B64
-Subparagraph o
-Clause i
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64_o_i&doctype=Appendix&subtype=B
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_NoncontrollingInterestInAcquireeRecognisedAtAcquisitionDate
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The percentage of voting equity interests acquired in a business combination. [Refer: Business combinations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph B64
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64_c&doctype=Appendix&subtype=B
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_PercentageOfVotingEquityInterestsAcquired
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The profit (loss) of the acquiree, since the acquisition date, included in the consolidated statement of comprehensive income. [Refer: Profit (loss)]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph B64
-Subparagraph q
-Clause i
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64_q_i&doctype=Appendix&subtype=B
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_ProfitLossOfAcquiree
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The profit (loss) of the combined entity as though the acquisition date for all business combinations that occurred during the year had been as of the beginning of the annual reporting period. [Refer: Business combinations [member]; Profit (loss)]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph B64
-Subparagraph q
-Clause ii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B64_q_ii&doctype=Appendix&subtype=B
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_ProfitLossOfCombinedEntity
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The proportion of the voting rights in a subsidiary held by the entity. [Refer: Subsidiaries [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 27
-IssueDate 2021-01-01
-Paragraph 17
-Subparagraph b
-Clause iii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=27&code=ifrs-tx-2021-en-r&anchor=para_17_b_iii&doctype=Standard
-URIDate 2021-03-24

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 27
-IssueDate 2021-01-01
-Paragraph 16
-Subparagraph b
-Clause iii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=27&code=ifrs-tx-2021-en-r&anchor=para_16_b_iii&doctype=Standard
-URIDate 2021-03-24

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2021-01-01
-Paragraph 19B
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_19B_c&doctype=Standard
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_ProportionOfVotingPowerHeldInSubsidiary
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of revenue of the acquiree since the acquisition date included in the consolidated statement of comprehensive income. [Refer: Revenue]

+ References

+ Details

Name:	ifrs-full_RevenueOfAcquiree
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The revenue of the combined entity as though the acquisition date for all business combinations that occurred during the year had been as of the beginning of the annual reporting period. [Refer: Business combinations [member]; Revenue]

+ References

+ Details

Name:	ifrs-full_RevenueOfCombinedEntity
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	ifrs-full_BusinessCombinationsAxis=bbu_DexKoGlobalIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SegmentsAxis=bbu_IndustrialsSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=bbu_BrookfieldBusinessPartnersL.P.AndInstitutionalInvestorsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: