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Fixed interest rate related to the interest rate derivative.

No definition available.

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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.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Date derivative contract ends, in YYYY-MM-DD format.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Nominal or face amount used to calculate payment on derivative.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
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Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

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Data Type:	xbrli:durationItemType
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Name:	srt_CounterpartyNameAxis=btsg_MorganStanleyMember
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Name:	srt_CounterpartyNameAxis=btsg_CreditAgricoleCorporateAndInvestmentBankMember
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