Debt Instrument, Allowed Prepayment, Amount

No definition available.

Name:	bw_DebtInstrumentAllowedPrepaymentAmount
Namespace Prefix:	bw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Debt Instrument, Annual Fees Agreed For Guaranty

+ References

No definition available.

+ Details

Name:	bw_DebtInstrumentAnnualFeesAgreedForGuaranty
Namespace Prefix:	bw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Payment To Related Party In Exchange For Debt Prepayment

+ References

No definition available.

+ Details

Name:	bw_PaymentToRelatedPartyInExchangeForDebtPrepayment
Namespace Prefix:	bw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Related Party Costs Per Month

+ References

No definition available.

+ Details

Name:	bw_RelatedPartyCostsPerMonth
Namespace Prefix:	bw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Related Party Transaction, Indemnity Rider Fee

+ References

No definition available.

+ Details

Name:	bw_RelatedPartyTransactionIndemnityRiderFee
Namespace Prefix:	bw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Related Party Transaction, Indemnity Rider Fee, Percentage Of Bonded Obligation

+ References

No definition available.

+ Details

Name:	bw_RelatedPartyTransactionIndemnityRiderFeePercentageOfBondedObligation
Namespace Prefix:	bw_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Related Party Transaction, Period With Written Notice To Terminate Agreement

+ References

No definition available.

+ Details

Name:	bw_RelatedPartyTransactionPeriodWithWrittenNoticeToTerminateAgreement
Namespace Prefix:	bw_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Related Party Transaction, Surety Issued By Payment And Performance Bond

+ References

No definition available.

+ Details

Name:	bw_RelatedPartyTransactionSuretyIssuedByPaymentAndPerformanceBond
Namespace Prefix:	bw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Sale Of Stock, Aggregate Amount Offered

+ References

No definition available.

+ Details

Name:	bw_SaleOfStockAggregateAmountOffered
Namespace Prefix:	bw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124429444&loc=SL124452920-239629

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69C
-URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69B
-URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612

+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of the required periodic payments applied to interest.

+ 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 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

Expense related to distribution, servicing and underwriting fees.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.14)
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

+ Details

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

- Definition

Percentage investment held by the managing member or general partner of the limited liability company (LLC) or limited partnership (LP).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

+ Details

Name:	us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPManagingMemberOrGeneralPartnerOwnershipInterest
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cash outflow for cost from early extinguishment and prepayment of debt. Includes, but is not limited to, third-party cost, premium paid, and other fee paid to lender directly for debt extinguishment or debt prepayment. Excludes accrued interest.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585

+ Details

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

- Definition

The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585

+ Details

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

- Definition

The cash outflow for cost incurred directly with the issuance of an equity security.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585

+ Details

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

- Definition

The percentage rate used to calculate dividend payments on preferred stock.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

+ Details

Name:	us-gaap_PreferredStockDividendRatePercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

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

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

- Definition

The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=bw_LastOutTermLoanTrancheAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=bw_SeniorNotes8125Due2026Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=bw_SeniorNotes650Due2026Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_SeriesAPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=bw_BPRIExecutiveConsultingLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=bw_FinancialAdvisoryServicesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=bw_B.RileyFinancialInc.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=bw_LastOutTermLoanTrancheA3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=bw_BRileySecuritiesIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=bw_BabcockWilcoxEnterprisesInc.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=bw_B.RileyCapitalManagementLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

RELATED PARTY TRANSACTIONS (Details) € in Millions											1 Months Ended	3 Months Ended		12 Months Ended
RELATED PARTY TRANSACTIONS (Details) € in Millions	Mar. 31, 2022 USD ($)	Dec. 30, 2021 USD ($)	Dec. 17, 2021 USD ($)	Dec. 17, 2021 EUR (€)	Dec. 13, 2021 USD ($)	Jun. 01, 2021 USD ($) shares	May 26, 2021 USD ($) shares	May 07, 2021 USD ($)	Feb. 12, 2021 USD ($) shares	Nov. 19, 2018 USD ($)	May 31, 2021 shares	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021	Dec. 28, 2021 USD ($)	Jul. 07, 2021 USD ($)	Jun. 30, 2021 USD ($)
Related Party Transaction [Line Items]
Payment of debt issuance costs												$ 119,000	$ 7,727,000
Sale of stock, number of shares issued (in shares) \| shares									29,487,180
Last Out Term Loan Tranche A \| Senior notes
Related Party Transaction [Line Items]
Debt instrument, allowed prepayment, amount									$ 35,000,000
8.125% Senior Notes due 2026 \| Senior notes
Related Party Transaction [Line Items]
Debt interest rate per annum									8.125%
6.50% Senior Notes \| Senior notes
Related Party Transaction [Line Items]
Debt interest rate per annum		6.50%													6.50%	6.50%
Debt face amount																$ 11,400,000
Underwriting fees and other transaction cost related to overallotment		$ 500,000
7.75% Series A Cumulative Perpetual Preferred Stock
Related Party Transaction [Line Items]
Preferred stock, dividend rate											7.75%
Sale of stock, number of shares issued (in shares) \| shares							444,700				4,444,700
BPRI Executive Consulting, LLC \| Financial advisory services
Related Party Transaction [Line Items]
Related party transaction, period with written notice to terminate agreement										30 days
Related party transaction monthly payments										$ 750,000
B. Riley Financial, Inc.
Related Party Transaction [Line Items]
Total fees												200,000	200,000
Performance bond amount \| €				€ 30.0
Indemnity rider fee			$ 1,700,000
Indemnity rider fee, percentage of bonded obligation			5.00%	5.00%
B. Riley Financial, Inc. \| Reimbursement agreement
Related Party Transaction [Line Items]
Annual fees agreed for guaranty																		$ 900,000
B. Riley Financial, Inc. \| Senior notes
Related Party Transaction [Line Items]
Debt face amount									$ 35,000,000
B. Riley Financial, Inc. \| Last Out Term Loan Tranche A-3
Related Party Transaction [Line Items]
Payment to related party in exchange for debt prepayment						$ 400,000
Cash paid for accrued interest						900,000
Debt prepayment amount						$ 73,300,000
B. Riley Financial, Inc. \| 7.75% Series A Cumulative Perpetual Preferred Stock
Related Party Transaction [Line Items]
Sale of stock, number of shares issued (in shares) \| shares						2,916,880
B. Riley Securities, Inc.
Related Party Transaction [Line Items]
Payments of stock issuance costs	$ 200,000								9,500,000
Stock sale agreement, aggregate amount offered (up to)																	$ 76,000,000
B. Riley Securities, Inc. \| Senior notes
Related Party Transaction [Line Items]
Payment of debt issuance costs									$ 5,200,000
B. Riley Securities, Inc. \| 8.125% Senior Notes due 2026 \| Senior notes
Related Party Transaction [Line Items]
Payment of debt issuance costs												$ 100,000		$ 600,000
Debt face amount													$ 150,000,000
B. Riley Securities, Inc. \| 6.50% Senior Notes \| Senior notes
Related Party Transaction [Line Items]
Payment of debt issuance costs					$ 5,500,000
B. Riley Securities, Inc. \| 7.75% Series A Cumulative Perpetual Preferred Stock
Related Party Transaction [Line Items]
Payment of debt issuance costs							$ 400,000	$ 4,300,000
Babcock & Wilcox Enterprises, Inc. \| B. Riley Capital Management, LLC
Related Party Transaction [Line Items]
Ownership percent of common stock												30.30%