Debt Instrument, Covenant, Consolidated EBITDA to Consolidated Cash Interest Expense

No definition available.

Name:	b_DebtInstrumentCovenantConsolidatedEBITDAtoConsolidatedCashInterestExpense
Namespace Prefix:	b_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Covenant, Consolidated Senior Debt to Consolidated EBITDA

+ References

No definition available.

+ Details

Name:	b_DebtInstrumentCovenantConsolidatedSeniorDebttoConsolidatedEBITDA
Namespace Prefix:	b_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Covenant, Material Acquisition, Consolidated Senior Credit to Consolidated EBITDA

+ References

No definition available.

+ Details

Name:	b_DebtInstrumentCovenantMaterialAcquisitionConsolidatedSeniorCredittoConsolidatedEBITDA
Namespace Prefix:	b_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Covenant, Material Acquisition, Total Consolidated Debt to Consolidated EBITDA

+ References

No definition available.

+ Details

Name:	b_DebtInstrumentCovenantMaterialAcquisitionTotalConsolidatedDebttoConsolidatedEBITDA
Namespace Prefix:	b_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Covenant, Threshold for Permitted Acquisition

+ References

No definition available.

+ Details

Name:	b_DebtInstrumentCovenantThresholdforPermittedAcquisition
Namespace Prefix:	b_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Debt Instrument, Covenant, Total Consolidated Debt to Consolidated EBITDA

+ References

No definition available.

+ Details

Name:	b_DebtInstrumentCovenantTotalConsolidatedDebttoConsolidatedEBITDA
Namespace Prefix:	b_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Prepayment Percentage of Principal Amount

+ References

No definition available.

+ Details

Name:	b_DebtInstrumentPrepaymentPercentageofPrincipalAmount
Namespace Prefix:	b_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line of credit facility with accordian feature, maximum borrowing capacity

+ References

No definition available.

+ Details

Name:	b_LineofCreditFacilityWithAccordianFeatureMaximumBorrowingCapacity
Namespace Prefix:	b_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Repayment period

+ References

No definition available.

+ Details

Name:	b_RepaymentPeriod
Namespace Prefix:	b_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of liabilities incurred by the acquirer as part of consideration transferred in a business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6578-128477

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 25
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6405-128476

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6613-128477

+ Details

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

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

Reference 3: 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=6877327&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
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://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=114775744&loc=d3e28551-108399

Reference 2: 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

+ 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:	num:percentItemType
Balance Type:	na
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_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The effective interest rate at the end of the reporting period.

+ References

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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

- 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=118932676&loc=d3e3291-108585

+ Details

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

- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ 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(19)(a))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16)(a)(1))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

- Details

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

- Details

Name:	srt_CurrencyAxis=currency_EUR
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=b_FourthAmendmentMaturityFebruary2022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CurrencyAxis=currency_GBP
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CurrencyAxis=currency_CHF
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=b_EuriborMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=b_FifthAmendmentMaturityFebruary2022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_BaseRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=b_FourthAmendmentMaturityFebruary2022AccordionFeatureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=b_SPAwithGimaticMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt (Narrative) (Details) € in Thousands		1 Months Ended	3 Months Ended	6 Months Ended
Debt (Narrative) (Details) € in Thousands	Sep. 19, 2018 USD ($)	Oct. 31, 2018	Dec. 31, 2018 USD ($)	Jun. 30, 2019 EUR (€)	Jun. 30, 2019 USD ($)	Dec. 31, 2018 EUR (€)	Dec. 31, 2018 USD ($)	Oct. 19, 2018 USD ($)	Dec. 31, 2017 USD ($)	Feb. 28, 2017 USD ($)	Oct. 31, 2014 USD ($)
Debt Instrument [Line Items]
Borrowings under lines of credit and overdrafts					$ 27,143,000		$ 2,137,000
Debt covenant ratio of senior debt to EBITDA				3.25	3.25
Debt covenant ratio of total debt to EBITDA				3.75	3.75
Debt covenant ratio of EBITDA to cash interest expense				4.25	4.25
Revolving Credit Agreement [Member]
Debt Instrument [Line Items]
Carrying amount of debt					$ 784,628,000		831,016,000
Line of credit facility, maximum borrowing capacity									$ 750,000,000
Line of credit facility with accordian feature, maximum borrowing capacity									$ 250,000,000
Remaining borrowing capacity					215,372,000		168,984,000
Revolving Credit Agreement [Member] \| Euro Member Countries, Euro
Debt Instrument [Line Items]
Carrying amount of debt				€ 492,680	$ 560,128,000	€ 470,350	$ 538,316,000
Stated interest rate				2.06%	2.06%	1.99%	1.99%
Revolving Credit Agreement [Member] \| International Subsidiary Borrowings [Member]
Debt Instrument [Line Items]
Carrying amount of debt				€ 44,100	$ 49,506,000	€ 179,000	$ 208,589,000
Senior Notes [Member] \| 3.97% Senior Notes [Member]
Debt Instrument [Line Items]
Carrying amount of debt					100,000,000		100,000,000
Stated interest rate											3.97%
Converted amount with accrued interest											$ 100,000,000
Percent allowed to be prepaid											100.00%
Lines of Credit [Member]
Debt Instrument [Line Items]
Borrowings under lines of credit and overdrafts					26,900,000		$ 2,041,000
Line of credit facility, maximum borrowing capacity					$ 87,000,000
Line of credit, interest rate at period end				3.16%	3.16%	0.17%	0.17%
Bank Overdrafts [Member]
Debt Instrument [Line Items]
Borrowings under lines of credit and overdrafts					$ 243,000		$ 96,000
Repayment period				2 days
Finance Leases [Member]
Debt Instrument [Line Items]
Carrying amount of debt					7,440,000		10,216,000
Foreign Bank Borrowings [Member]
Debt Instrument [Line Items]
Carrying amount of debt					524,000		$ 647,000
Revolving Credit Agreement [Member]
Debt Instrument [Line Items]
Debt covenant threshold for permitted acquisition					$ 150,000
Debt covenant material acquisition, senior credit to EBITDA				3.50	3.50
Debt covenant material acquisition, debt to EBITDA				4.25	4.25
Revolving Credit Agreement [Member] \| Fourth Amendment, Maturity February 2022 [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity										$ 850,000,000
Revolving Credit Agreement [Member] \| Fourth Amendment, Maturity February 2022 [Member] \| United Kingdom, Pounds
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity										600,000,000
Revolving Credit Agreement [Member] \| Fourth Amendment, Maturity February 2022 [Member] \| Euro Member Countries, Euro
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity										600,000,000
Revolving Credit Agreement [Member] \| Fourth Amendment, Maturity February 2022 [Member] \| Switzerland, Francs
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity										600,000,000
Revolving Credit Agreement [Member] \| Fourth Amendment, Maturity February 2022 [Member] \| Euribor [Member]
Debt Instrument [Line Items]
Stated interest rate		0.00%
Revolving Credit Agreement [Member] \| Fifth Amendment, Maturity February 2022 [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity								$ 1,000,000,000
Line of credit facility with accordian feature, maximum borrowing capacity								$ 200,000,000
Debt fees and expenses			$ 529,000
Revolving Credit Agreement [Member] \| Fifth Amendment, Maturity February 2022 [Member] \| one-month LIBOR [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Variable basis spread		1.10%
Revolving Credit Agreement [Member] \| Fifth Amendment, Maturity February 2022 [Member] \| one-month LIBOR [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Variable basis spread		1.70%
Revolving Credit Agreement [Member] \| Fifth Amendment, Maturity February 2022 [Member] \| Base Rate [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Variable basis spread		0.10%
Revolving Credit Agreement [Member] \| Fifth Amendment, Maturity February 2022 [Member] \| Base Rate [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Variable basis spread		0.70%
Revolving Credit Agreement [Member] \| Fifth Amendment, Maturity February 2022 [Member] \| Euribor [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Variable basis spread		1.10%
Revolving Credit Agreement [Member] \| Fifth Amendment, Maturity February 2022 [Member] \| Euribor [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Variable basis spread		1.70%
Revolving Credit Agreement [Member] \| Fourth Amendment, Maturity February 2022, Accordion Feature [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity										$ 350,000,000
SPA with Gimatic [Member]
Debt Instrument [Line Items]
Business Combination, Consideration Transferred, Liabilities Incurred	$ 150,000,000