COMMITMENTS AND CONTINGENCIES, Registration Rights (Details) $ in Millions	Mar. 31, 2021 USD ($)	Sep. 14, 2020 Demand Individual
Registration and Stockholder Rights [Abstract]
Number of individuals can be nominated for election in board of directors by 50% funders share holder		3
Number of individuals can be nominated for election in board of directors by 30% funders share holder		2
Number of individuals can be nominated for election in board of directors by 20% funders share holder		1
Securities offering price \| $	$ 50
Maximum [Member]
Registration and Stockholder Rights [Abstract]
Number of demands eligible security holder can make \| Demand		2
Minimum [Member]
Registration and Stockholder Rights [Abstract]
Threshold percentage of outstanding registrable securities holder, to make demand		20.00%

Represents the number of demands eligible security holder can make.

No definition available.

Name:	sbg_NumberOfDemandsEligibleSecurityHolderCanMake
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Represents the number of individuals can be nominated for election in board of directors by 20% funders share holder.

No definition available.

Name:	sbg_NumberOfIndividualsCanBeNominatedForElectionInBoardOfDirectorsBy20FundersShareHolder
Namespace Prefix:	sbg_
Data Type:	xbrli:integerItemType
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Represents the number of individuals can be nominated for election in board of directors by 30% funders share holder.

No definition available.

Name:	sbg_NumberOfIndividualsCanBeNominatedForElectionInBoardOfDirectorsBy30FundersShareHolder
Namespace Prefix:	sbg_
Data Type:	xbrli:integerItemType
Balance Type:	na
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Represents the number of individuals can be nominated for election in board of directors by 50% funders share holder.

No definition available.

Name:	sbg_NumberOfIndividualsCanBeNominatedForElectionInBoardOfDirectorsBy50FundersShareHolder
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Data Type:	xbrli:integerItemType
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No definition available.

Name:	sbg_RegistrationAndStockholderRightsAbstract
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Amount of underwritten offering price for securities.

No definition available.

Name:	sbg_SecuritiesMinimumExpectedOfferingPrice
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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Required percentage of outstanding registrable securities holder eligible to make demand.

No definition available.

Name:	sbg_ThresholdPercentageOfOutstandingRegistrableSecuritiesHolderToMakeDemand
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

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

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