Name:	bel_FairValueMeasurementWithUnobservableInputsDerivativeFinancialInstrumentsLiabilitiesCreditValueAdjustmentPercentageGreaterThanForClassificationToLevel3
Namespace Prefix:	bel_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the number of properties in Mexico for which the functional currency used for reporting purposes is other than the local currency.

No definition available.

Name:	bel_NumberOfPropertiesInMexicoForWhichLocalCurrencyIsNotApplicable
Namespace Prefix:	bel_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Amount of gain/(loss) arising on remeasurement of non-monetary assets and liabilities following a change in functional currency, included in other comprehensive income.

No definition available.

Name:	bel_OtherComprehensiveIncomeLossgainlossarisingonchangeinfunctionalcurrency
Namespace Prefix:	bel_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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.

No definition available.

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

Amount, after accumulated amortization, of debt issuance costs classified as noncurrent. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_DeferredFinanceCostsNoncurrentNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Expenditures for planning and executing the conception, pricing, promotion, and distribution of ideas, goods, and services. Costs of public relations and corporate promotions are typically considered to be marketing costs.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.4)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688